The present invention relates to the process of producing a polyol block copolymer from a two step process carried out in two separate reactors, and products and compositions incorporating such copolymers.

Background

WO2015059068 and US 2015/0259475 (Equivalent of EP2888309) from Covestro disclose the use of a DMC catalyst for the production of polyether carbonate polyols from CO2 and alkylene oxide in the presence of a starter compound. Many H-functional starter compounds are listed including polyether carbonate polyols, polycarbonate polyols and polycarbonates.

However, a DMC catalyst alone is limited in the amount of carbon dioxide it can incorporate into a polyethercarbonate polyol, requiring high pressures (generally more than 40 bar) to achieve a maximum of around 50 % of the possible CO2 incorporation. Furthermore, a DMC catalyst requires a pre-activation step, usually in the absence of CO2, which initially produces a polyether. CO2 is then added and incorporated into the polymer structure. This means that a DMC catalyst alone cannot produce low molecular weight polyols (e.g. <1000 Mn) with substantial CO2 content and the CO2 content of the polyol is even restricted at higher weights such as 2000 Mn. Polyethercarbonate polyols produced by a DMC alone generally have a structure which is rich in ether linkages in the centre of the polymer chain and richer in carbonate groups towards the hydroxyl terminal groups. This is not advantageous as the ether groups are substantially more stable to heat and basic conditions than the carbonate linkages.

WO2010062703 discloses production of block copolymers having a polycarbonate block and a hydrophilic block (e.g. a polyether). A two pot production is described, using a carbonate catalyst in the first reaction to produce an alternating polycarbonate block, followed by quenching of the reaction, isolation of the polyol from solvents and unreacted monomers and then a second batch reaction with a DMC catalyst (in the absence of CO2) to incorporate the hydrophilic oligomer, such as poly(alkylene oxide). The process can be used to produce B-A-B polymers where A is a polycarbonate and B is a hydrophilic block such as a polyether. The polymers have use in enhanced oil recovery.

The invention allows production of polycarbonate block polyether polyols containing significantly increased CO2 content under mild pressures by using low molecular weight CO2 containing polycarbonate polyols (produced by a carbonate catalyst in a first reaction) as starters for a reaction between DMC catalyst and epoxide. Unlike the polyether carbonate polyols produced by a DMC catalyst alone, the polycarbonate block polyether polyols produced by the invention can produce low molecular weight polyols (e.g. <1000 Mn) with substantial CO2 content (e.g. > 7wt%).

Advantageously, the low molecular weight polycarbonate polyols do not have to be isolated but can be made in one reactor and transferred directly into the second without removing any catalyst, or solvents.

WO2017037441 describes a process where a carbonate catalyst and a DMC catalyst are used in one reactor to produce a polyethercarbonate polyol. The conditions of the reaction must be balanced to meet the needs of two different catalysts.

Advantageously, the invention allows optimisation of the conditions for use of two different types of catalyst, a carbonate catalyst and a DMC catalyst, enabling optimisation of conditions for each catalyst individually rather than compromising to suit the overall system. The high carbonate content polyol can also be added directly to a pre-activated DMC catalyst, which is more desirable as it reduces cycle times and increases process safety by limiting unreacted epoxide content in the reactor.

Furthermore, the invention can be used to produce polycarbonate block polyether polyol block copolymers which contain a core of high carbonate content chains with a terminal block of polyether chains. Polyurethanes made from such polyols benefit from the advantages of high carbonate linkages (e.g. increased strength, increased chemical resistance, resistance to both hydrolysis and oil etc) whilst still retaining the higher thermal stability that ether end blocks provide. The polyols can advantageously be made using the same or similar epoxide reactants in both reactions.

Summary of the Invention

According to the first aspect of the present invention, there is also provided a process for producing a polyol block copolymer in a multiple reactor system; the system comprising a first and second reactor wherein a first reaction takes place in the first reactor and a second reaction takes place in the second reactor; wherein the first reaction is the reaction of a carbonate catalyst with CO2 and epoxide, in the presence of a starter and/or solvent to produce a polycarbonate polyol copolymer and the second reaction is the reaction of a DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce a polyol block copolymer, wherein the product of the first reaction is fed into the second reactor as a crude reaction mixture, (ii) the epoxide and the polycarbonate polyol compound of the first reaction are fed into the second reactor in a continuous or semi-batch manner, and/or (iii) the product of the first reaction has a neutral or alkaline pH on addition to the second reaction.

According to the second aspect of the present invention, there is also provided a process process for producing a polyol block copolymer in a multiple reactor system; the system comprising a first and second reactor wherein a first reaction takes place in the first reactor and a second reaction takes place in the second reactor; wherein the first reaction is the reaction of a carbonate catalyst with CO2 and epoxide, in the presence of a polyfunctional starter, and optionally a solvent, to produce a polycarbonate polyol and the second reaction is the semi-batch or continuous reaction of a DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce a polyol block copolymer.

Adding the components in the separate reactions and reactors may be useful to increase activity of the catalysts and may lead to a more efficient process, compared with a process in which all of the materials are provided at the start of one reaction. Large amounts of some of the components present throughout the reaction may reduce efficiency of the catalysts. Reacting this material in separate reactors may prevent this reduced efficiency of the catalysts and/or may optimise catalyst activity. The reaction conditions of each reactor can be tailored to optimise the reactions for each catalyst.

Additionally, not loading the total amount of each component at the start of the reaction and having the catalyst for the first reaction in a separate reactor to the catalyst for the second reaction, may lead to even catalysis, and more uniform polymer products. This in turn may lead to polymers having a narrower molecular weight distribution, desired ratio and distribution along the chain of ether to carbonate linkages, and/or improved polyol stability. Having the reactions with the two different catalysts separate and mixing only certain components in the first reaction and adding the remainder in the second reaction may also be useful as the DMC catalyst can be pre-activated. Such pre-activation may be achieved by mixing one or both catalysts with epoxide (and optionally other components). Pre activation of the DMC catalyst is useful as it enables safe control of the reaction (preventing uncontrolled increase of unreacted monomer content) and removes unpredictable activation periods.

It will be appreciated that the present invention relates to a reaction in which carbonate and/or ether linkages are added to a growing polymer chain. Having separate reactions allows the first reaction to proceed before a second stage in the reaction. Mixing epoxide, carbonate catalyst, starter compound and carbon dioxide, may permit growth of a polymer having a high number of carbonate linkages. Thereafter, adding the products to the DMC catalyst in the absence of CO2 permits the reaction to proceed by adding ether linkages to the growing polymer chain. Ether linkages are more thermally stable than carbonate linkages and less prone to degradation by bases such as the amine catalysts used in PU formation. Therefore, applications get the benefits of high carbonate linkages (such as increased strength, chemical resistance, both oil and hydrolysis resistance etc) that are introduced from the A block whilst retaining the stability of the polyol through the ether linkages from the B blocks at the ends of the polymer chains.

In general terms, an aim of the present invention is to control the polymerisation reaction through a two-reactor system, to increase CO2 content of the polyols at low pressures (enabling more cost effective processes and plant design) and making a product that has high CO2 content but good stability and application performance. The processes herein may allow the product prepared by such processes to be tailored to the necessary requirements.

The polyol block copolymers of the present invention may be prepared from a suitable epoxide and carbon dioxide in the presence of a starter compound and a carbonate catalyst for the first reaction; and then a suitable epoxide in the presence of a double metal cyanide (DMC) catalyst in the second reaction.

Although typically any residual CO2 from the first reaction may be removed from the crude reaction product of the first reaction prior to commencement of the second reaction such that the second reaction is carried out without CO2, it will be appreciated that a small amount of CO2 may be present in the second reaction mixture as an unused reagent of the first reaction.

Typically the first reaction mixture contains less than 5% CO2 by weight of the reaction mixture prior to addition to the second reaction, preferably less than 2.5%, such as less than 1.0%, less than 0.5% or less than 0.1 %. Typically, the second reaction is carried out without the independent addition of CO2. The polyether block produced in the second reaction may have less than 1 % carbonate linkages, preferably less than 0.5% carbonate linkages, more preferably less than 0.1 % carbonate linkages. Preferably the polyether block produced in the second reaction is substantially free from carbonate linkages.

Typically, therefore the second reaction is carried out substantially in the absence of CO2. Accordingly, by substantially in the absence of CO2 is meant that the second reaction is carried out in the presence of less than 4% CO2 by weight, preferably less than 2%, such as less than 1.0%, less than 0.5% or less than 0.1% by weight of total reactants, catalyst and products in the second reaction.

By a crude reaction mixture is meant that the product of the reaction is typically not isolated prior to addition of the reaction mixture ot the second reaction. Preferably, the reaction mixture undergoes no further processing steps prior to its addition to the second reaction. The carbonate catalyst of the present invention may be a catalyst that produces a polycarbonate polyol with greater than 76% carbonate linkages, preferably greater than 80% carbonate linkages, more preferably greater than 85% carbonate linkages, most preferably greater than 90% carbonate linkages may be present in block A.

If the epoxide used is asymmetric (e.g. propylene oxide), the catalyst may produce polycarbonate polyols with a high proportion of head to tail linkages, such as greater than 70%, greater than 80% or greater than 90% head to tail linkages. Alternatively, the catalyst may produce polycarbonate polyols with no stereoselectivity, producing polyols with approximately 50% head to tail linkages.

The carbonate catalyst may be heterogeneous or homogeneous.

The carbonate catalyst may be a mono-metallic, bimetallic or multi-metallic homogeneous complex.

The carbonate catalyst may comprise phenol or phenolate ligands.

Typically, the carbonate catalyst may be a bimetallic complex comprising phenol or phenolate ligands. The two metals may be the same or different.

The carbonate catalyst may be a catalyst of formula (IV):

wherein:

M is a metal cation represented by M-(L)V;

x is an integer from 1 to 4, preferably x is 1 or 2;

a multidentate ligand or plurality of multidentate ligands;

L is a coordinating ligand, for example, L may be a neutral ligand, or an anionic ligand that is capable of ring-opening an epoxide;

v is an integer that independently satisfies the valency of each M, and/or the preferred coordination geometry of each M or is such that the complex represented by formula (IV) above has an overall neutral charge. For example, each v may independently be 0, 1 , 2 or 3, e.g. v may be 1 or 2. When v > 1 , each L may be different.

The term multidentate ligand includes bidentate, tridentate, tetradentate and higher dentate ligands. Each multidentate ligand may be a macrocyclic ligand or an open ligand.

Such catalysts include those in WO2010022388 (metal salens and derivatives, metal porphyrins, corroles and derivatives, metal tetraaza annulenes and derivatives), W02010028362 (metal salens and derivatives, metal porphyrins, corroles and derivatives, metal tetraaza annulenes and derivatives), W02008136591 (metal salens), WO2011105846 (metal salens), WO2014148825 (metal salens), WO2013012895 (metal salens),

EP2258745A1 (metal porphyrins and derivatives), JP2008081518A (metal porphyrins and derivatives), CN101412809 (metal salens and derivatives), WO2019126221 (metal aminotriphenol complexes), US9018318 (metal beta-diiminate complexes), US6133402A (metal beta-diiminate complexes) and US8278239 (metal salens and derivatives), the entire contents of which, especially, insofar as they relate to suitable carbonate catalysts for the reaction of CO2 and epoxide, in the presence of a starter and optionally a solvent to produce a polycarbonate polyol copolymer as defined herein are incorporated herein by reference.

Such catalysts also include those in W02009/130470, WO2013/034750, WO2016/012786, WO2016/012785, WO2012037282 and WO2019048878A1 (all bimetallic phenolate complexes), the entire contents of which, especially, insofar as they relate to suitable carbonate catalysts for the reaction of CO2 and epoxide, in the presence of a starter and optionally a solvent to produce a polycarbonate polyol copolymer as defined herein are incorporated herein by reference.

The carbonate catalyst may have the following structure:

wherein:

Mi and M2 are independently selected from Zn(ll), Cr(ll), Co(ll), Cu(ll), Mn(ll), Mg(ll), Ni(ll),

Fe(ll), Ti(ll), V(ll), Cr(lll)-X, Co(lll)-X, Mn(lll)-X, Ni(lll)-X, Fe(lll)-X, Ca(ll), Ge(ll), Al(lll)-X,

Ti(lll)-X, V(lll)-X, Ge(IV)-(X)2, Y(IN)-X, Sc(lll)-X or Ti(IV)-(X)2;

Ri and R2 are independently selected from hydrogen, halide, a nitro group, a nitrile group, an imine, an amine, an ether, a silyl group, a silyl ether group, a sulfoxide group, a sulfonyl group, a sulfinate group or an acetylide group or an optionally substituted alkyl, alkenyl, alkynyl, haloalkyl, aryl, heteroaryl, alkoxy, aryloxy, alkylthio, arylthio, alicyclic or heteroalicyclic group;

R3 is independently selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene, heteroarylene or cycloalkylene,

wherein alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene and heteroalkynylene, may optionally be interrupted by aryl, heteroaryl, alicyclic or heteroalicyclic;

R5 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl or alkylaryl;

Ei is C, E2 is O, S or NH or Ei is N and E2 is O;

E3, E4, E5 and Eb are selected from N, NR4, O and S, wherein when E3, E4, E5 or Ee are N,

- is , and wherein when E3, E4, E5 or Ee are NR4, O or S, - is - ;

R4 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl, -alkylC(0)0Ri9 or -alkylCºN or alkylaryl;

X is independently selected from 0C(0)Rx, 0S02Rx, OSORx, OSO(Rx)2, S(0)Rx, ORx, phosphinate, phosphonate, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, wherein each X may be the same or different and wherein X may form a bridge between Mi and M2;

Rx is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl; and

G is absent or independently selected from a neutral or anionic donor ligand which is a Lewis base.

Each of the occurrences of the groups Ri and R2 may be the same or different, and Ri and R2 can be the same or different.

DMC catalysts are complicated compounds which comprise at least two metal centres and cyanide ligands. The DMC catalyst may additionally comprise at least one of: one or more complexing agents, water, a metal salt and/or an acid (e.g. in non-stoichiometric amounts). The first two of the at least two metal centres may be represented by M’ and M”.

M’ may be selected from Zn(ll), Ru(ll), Ru(lll), Fe(ll), Ni(ll), Mn(ll), Co(ll), Sn(ll), Pb(ll), Fe(lll), Mo(IV), Mo(VI), Al(lll), V(V), V(VI), Sr(ll), W(IV), W(VI), Cu(ll), and Cr(lll), M’ is optionally selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), optionally M’ is Zn(ll).

M” is selected from Fe(ll), Fe(lll), Co(ll), Co(lll), Cr(ll), Cr(lll), Mn(ll), Mn(lll), Ir(lll), Ni(ll), Rh(lll), Ru(ll), V(IV), and V(V), optionally M” is selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll), optionally M” is selected from Co(ll) and Co(lll).

It will be appreciated that the above optional definitions for M’ and M” may be combined. For example, optionally M’ may be selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), and M” may

optionally be selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll). For example, M’ may optionally be Zn(ll) and M” may optionally be selected from Co(ll) and Co(lll).

If a further metal centre(s) is present, the further metal centre may be further selected from the definition of M’ or M”.

Examples of DMC catalysts which can be used in the process of the invention include those described in US 3,427,256, US 5,536,883, US 6,291 ,388, US 6,486,361 , US 6,608,231 , US 7,008,900, US 5,482,908, US 5,780,584, US 5,783,513, US 5,158,922, US 5,693,584, US 7,811 ,958, US 6,835,687, US 6,699,961 , US 6,716,788, US 6,977,236, US 7,968,754, US 7,034,103, US 4,826,953, US 4,500 704, US 7,977,501 , US 9,315,622, EP-A-1568414, EP-A-1529566, and WO 2015/022290, the entire contents of which, especially, insofar as they relate to DMC catalysts for the production of the block copolymer as defined herein or reactions as defined herein, are incorporated herein by reference.

It will be appreciated that the DMC catalyst may comprise:

M’d[M”e(CN)f]g

wherein M’ and M” are as defined above, d, e, f and g are integers, and are chosen such that the DMC catalyst has electroneutrality. Optionally, d is 3. Optionally, e is 1. Optionally f is 6. Optionally g is 2. Optionally, M’ is selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), optionally M’ is Zn(ll). Optionally M” is selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll), optionally M” is Co(ll) or Co(lll).

It will be appreciated that any of these optional features may be combined, for example, d is 3, e is 1 , f is 6 and g is 2, M’ is Zn(ll) and M” is Co(lll).

Suitable DMC catalysts of the above formula may include zinc hexacyanocobaltate(lll), zinc hexacyanoferrate(lll), nickel hexacyanoferrate(ll), and cobalt hexacyanocobaltate(lll).

There has been a lot of development in the field of DMC catalysts, and the skilled person will appreciate that the DMC catalyst may comprise, in addition to the formula above, further additives to enhance the activity of the catalyst. Thus, while the above formula may form the “core” of the DMC catalyst, the DMC catalyst may additionally comprise stoichiometric or non-stoichiometric amounts of one or more additional components, such as at least one complexing agent, an acid, a metal salt, and/or water.

For example, the DMC catalyst may have the following formula:

M’d[M”e(CN)f]g hM”’X”i jRc kH20 IHrX’”

wherein M’, M”, X’”, d, e, f and g are as defined above. M’” can be M’ and/or M”. X” is an anion selected from halide, oxide, hydroxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, optionally X” is halide i is

an integer of 1 or more, and the charge on the anion X” multiplied by i satisfies the valency of M’”. r is an integer that corresponds to the charge on the counterion X”. For example, when X’” is Cl , r will be 1. I is 0, or a number between 0.1 and 5. Optionally, I is between 0.15 and 1.5.

Rc is a complexing agent or a combination of one or more complexing agents. For example, Rc may be a (poly)ether, a polyether carbonate, a polycarbonate, a poly(tetramethylene ether diol), a ketone, an ester, an amide, an alcohol (e.g. a Ci-e alcohol), a urea and the like, such as propylene glycol, polypropylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, 3-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol or a combination thereof, for example, Rc may be tert-butyl alcohol, dimethoxyethane, or polypropylene glycol.

As indicated above, more than one complexing agent may be present in the DMC catalysts used in the present invention. Optionally one of the complexing agents of Rc may be a polymeric complexing agent. Optionally, Rc may be a combination of a polymeric complexing agent and a non-polymeric complexing agent.. Optionally, a combination of the complexing agents tert-butyl alcohol and polypropylene glycol may be present.

It will be appreciated that if the water, complexing agent, acid and/or metal salt are not present in the DMC catalyst, h, j, k and/or I will be zero respectively. If the water, complexing agent, acid and/or metal salt are present, then h, j, k and/or I are a positive number and may, for example, be between 0 and 20. For example, h may be between 0.1 and 4. j may be between 0.1 and 6. k may be between 0 and 20, e.g. between 0.1 and 10, such as between 0.1 and 5. I may be between 0.1 and 5, such as between 0.15 and 1.5.

The polymeric complexing agent is optionally selected from a polyether, a polycarbonate ether, and a polycarbonate. The polymeric complexing agent may be present in an amount of from about 5% to about 80% by weight of the DMC catalyst, optionally in an amount of from about 10% to about 70% by weight of the DMC catalyst, optionally in an amount of from about 20% to about 50% by weight of the DMC catalyst.

The DMC catalyst, in addition to at least two metal centres and cyanide ligands, may also comprise at least one of: one or more complexing agents, water, a metal salt and/or an acid, optionally in non-stoichiometric amounts.

An exemplary DMC catalyst is of the formula Zn3[Co(CN)6]2 hZnCh khhO j[(CH3)3COH], wherein h, k and j are as defined above. For example, h may be from 0 to 4 (e.g. from 0.1 to 4), k may be from 0 to 20 (e.g. from 0.1 to 10), and j may be from 0 to 6 (e.g. from 0.1 to 6).As set out above, DMC catalysts are complicated structures, and thus, the above formulae including the additional components is not intended to be limiting. Instead, the

skilled person will appreciate that this definition is not exhaustive of the DMC catalysts which are capable of being used in the invention.

The DMC catalyst may be pre-activated. Such pre-activation may be achieved by mixing one or both catalysts with alkylene oxide (and optionally other components). Pre-activation of the DMC catalyst is useful as it enables safe control of the reaction (preventing uncontrolled increase of unreacted monomer content) and removes unpredictable activation periods. Optionally, the DMC catalyst may be pre-activated in reactor 2 or separately. Optionally, the DMC catalyst may be pre-activated with a starter compound or with the reaction product of the first or second reaction. When the DMC catalyst is pre-activated with the reaction product of the first reaction, it may be pre-activated with some or all of the reaction product of the first reaction. The DMC catalyst may be pre-activated with the polyol block copolymer product which may be added into the reactor, or may be the remaining product from a previous reaction, the so-called‘reaction heel’.

The starter compound which may be used in the processes for forming polycarbonate polyols of the present invention comprises at least one group, preferably at least two groups, selected from a hydroxyl group (-OH), a thiol (-SH), an amine having at least one N-H bond (-NHR’), a group having at least one P-OH bond (e.g. -PR’(0)0H, PR’(0)(0H)2 or -P(0)(0R’)(0H)), or a carboxylic acid group (-C(O)OH).

Where the starter is a polyfunctional starter compound, the starter compound comprises at least two groups selected from a hydroxyl group (-OH), a thiol (-SH), an amine having at least one N-H bond (-NHR’), a group having at least one P-OH bond (e.g. -PR’(0)0H, PR’(0)(0H)2 or -P(0)(0R’)(0H)), or a carboxylic acid group (-C(O)OH).

Thus, the starter compound which may be used in the processes for forming polycarbonate ether polyols may be of the formula (III):

Z-( Rz)a (III)

Z can be any group which can have 1 or more -Rz groups attached to it, preferably 2 or more -Rz groups attached to it. Thus, Z may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene, heteroalkyl heteroarylene or alkylheteroarylene group. Optionally Z is alkylene, heteroalkylene, arylene, or heteroarylene.

a is an integer which is at least 1 , preferably at least 2, optionally a is in the range of between 1 and 8, optionally a is in the range of between 2 and 6.

Each Rz may be -OH, -NHR’, -SH, -C(0)0H, -P(0)(0R’)(0H), -PR’(0)(0H)2 or -PR’(0)OH, optionally Rz is selected from -OH, -NHR’ or -C(0)0H, optionally each Rz is -OH, -C(0)0H or a combination thereof (e.g. each Rz is -OH).

R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, optionally R’ is H or optionally substituted alkyl.

Z’ corresponds to Rz, except that a bond replaces the labile hydrogen atom. Therefore, the identity of each Z’ depends on the definition of Rz in the starter compound. Thus, it will be appreciated that each Z’ may be -0-, -NR’-, -S-, -C(0)0-, -P(0)(0R’)0-, -PR’(0)(0-)2 or -PR’(0)0- (wherein R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, preferably R’ is H or optionally substituted alkyl), preferably 71 may be -C(0)0-, -NR’- or -0-, more preferably each Z’ may be -0-, -C(0)0- or a combination thereof, more preferably each Z’ may be -0-.

More than one starter compound may be present in each reaction. The starter compounds for the first and second reaction may be the same or different. Where there are two different starter compounds, there may be two starter compounds in the second reaction, wherein the starter compound in the first reaction is a first starter compound, and wherein the second reaction comprises adding the first crude reaction mixture to the second reactor comprising a second starter compound and double metal cyanide (DMC) catalyst and, optionally, solvent and/or epoxide. The second reaction of the present invention may be conducted at least about 1 minutes after the first reaction, optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours. It will be appreciated that in a continuous reaction these periods are the average period from addition of monomer in the first reactor to transfer of monomer residue into the second reactor.

If polymeric, the starter compound may have a molecular weight of at least about 200 Da or of at most about 1000 Da.

For example, having a molecular weight of about 200 to 1000 Da, optionally about 300 to 700 Da, optionally about 400 Da.

The or each starter compound typically has one or more Rz groups, optionally two or more, optionally three or more, optionally four or more, optionally five or more, optionally six or more, optionally seven or more, optionally eight or more Rz groups, particularly wherein Rz is hydroxyl.

It will be appreciated that any of the above features may be combined. For example, a may be between 1 and 8, each Rz may be -OH, -C(0)OH or a combination thereof, and Z may be selected from alkylene, heteroalkylene, arylene, or heteroarylene.

Exemplary starter compounds for either reaction include monofunctional starter substances such as alcohols, phenols, amines, thiols and carboxylic acids; for example, alcohols such as methanol, ethanol, 1- and 2-propanol, 1- and 2-butanol, linear or branched C3-C20-monoalcohol such as tert-butanol, 3-buten-1-ol, 3-butyn-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, propargyl alcohol, 2-methyl-2-propanol, 1-tert-butoxy-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 1-decanol, 1-dodecanol, phenol, 2-hydroxybiphenyl, 3-hydroxybiphenyl, 4-hydroxybiphenyl, 2-hydroxypyridine, 3-hydroxypyridine, and 4-hydroxypyridine, mono-ethers or esters of ethylene, propylene, polyethylene; polypropylene glycols such as ethylene glycol mono-methyl ether and propylene glycol mono-methyl ether, phenols such as linear or branched C3-C20 alkyl substituted phenols, for example nonyl-phenols or octyl phenols monofunctional carboxylic acids such as formic acid, acetic acid, propionic acid and butyric acid, fatty acids, such as stearic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid and acrylic acid, and monofunctional thiols such as ethanethiol, propane-1 -thiol, propane-2-thiol, butane-1 -thiol, 3-methylbutane-1 -thiol, 2-butene-1-thiol, and thiophenol, or amines such as butylamine, tert-butylamine, pentylamine, hexylamine, aniline, aziridine, pyrrolidine, piperidine, and morpholine; and/or selected from diols such as 1 ,2-ethanediol (ethylene glycol), 1 -2-propanediol, 1 ,3-propanediol (propylene glycol), 1 ,2-butanediol, 1-3-butanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,8-octanediol, 1 ,10-decanediol, 1 ,12-dodecanediol, 1 ,4-cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425, PPG 725, PPG 1000 and the like, triols such as glycerol, benzenetriol, 1 ,2,4-butanetriol, 1 ,2,6-hexanetriol, tris(methylalcohol)propane, tris(methylalcohol)ethane, tris(methylalcohol)nitropropane, trimethylol propane, polyethylene oxide triols, polypropylene oxide triols and polyester triols, tetraols such as calix[4]arene, 2,2-bis(methylalcohol)-1 ,3-propanediol, erythritol, pentaerythritol or polyalkylene glycols (PEGs or PPGs) having 4-OH groups, polyols, such as sorbitol or polyalkylene glycols (PEGs or PPGs) having 5 or more -OH groups, or compounds having mixed functional groups including ethanolamine, diethanolamine, methyldiethanolamine, and phenyldiethanolamine.

For example, the starter compound may be a monofunctional alcohol such as ethanol, 1-propanol, 2-propanol, 1 -butanol, 2-butanol, 1-hexanol, 1-octanol, 1-decanol, 1-dodecanol, a phenol such as nonyl-phenol or octyl phenol or a mono-functional carboxylic acid such as

formic acid, acetic acid, propionic acid, butyric acid, fatty acids, such as stearic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, acrylic acid.

For example, the starter compound may be a diol such as 1 ,2-ethanediol (ethylene glycol), 1 -2-propanediol, 1 ,3-propanediol (propylene glycol), 1 ,2-butanediol, 1-3-butanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,8-octanediol, 1 ,10-decanediol, 1 ,12-dodecanediol, 1 ,4-cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, poly(caprolactone) diol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425, PPG 725, PPG 1000 and the like. It will be appreciated that the starter compound may be 1 ,6-hexanediol, 1 ,4-cyclohexanedimethanol, 1 ,12-dodecanediol, poly(caprolactone) diol, PPG 425, PPG 725, or PPG 1000. Preferably the the starter compound may be a diol such as 1 ,2-ethanediol (ethylene glycol), 1 ,3-propanediol (propylene glycol), 1 ,2-butanediol, 1-3-butanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,8-octanediol, 1 ,10-decanediol, 1 ,12-dodecanediol, 1 ,4-cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, poly(caprolactone) diol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425, PPG 725, PPG 1000 and the like. It will be appreciated that the starter compound may be 1 ,6-hexanediol, 1 ,4-cyclohexanedimethanol, 1 ,12-dodecanediol, poly(caprolactone) diol, PPG 425, PPG 725, or PPG 1000.

Further exemplary starter compounds may include diacids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid or other compounds having mixed functional groups such as lactic acid, glycolic acid, 3-hydroxypropanoic acid, 4-hydroxybutanoic acid, 5-hydroxypentanoic acid.

The ratio of the starter compound, if present, to the carbonate catalyst may be in amounts of from about 1000:1 to about 1 :1 , for example, from about 750:1 to about 5:1 , such as from about 500:1 to about 10:1 , e.g. from about 250:1 to about 20:1 , or from about 125:1 to about 30:1 , or from about 50:1 to about 20:1. These ratios are molar ratios. These ratios are the ratios of the total amount of starter to the total amount of the carbonate catalyst used in the processes. These ratios may be maintained during the course of addition of materials.

The DMC catalyst may be pre-activated. Optionally, the DMC catalyst may be pre-activated in reactor 2 or separately. Optionally, the DMC catalyst may be pre-activated with a starter compound or with the reaction product of the first or second reaction. When the DMC

catalyst is pre-activated with the reaction product of the first reaction, it may be pre-activated with some or all of the reaction product of the first reaction. The DMC catalyst may be pre activated with the polyol block copolymer product which may be added into the reactor, or may be the remaining product from a previous reaction, the so-called‘reaction heel’.

The product of the first reaction may be a low molecular weight polycarbonate polyol. The preferred molecular weight (Mn) of the polycarbonate polyol depends on the preferred overall molecular weight of the polyol block copolymer. The molecular weight (Mn) of the polycarbonate polyol may be in the range from about 200 to about 4000 Da, from about 200 to about 2000 Da, from about 200 to about 1000 Da, or from about 400 to about 800 Da, as measured by Gel Permeation Chromatography.

The first reaction may produce a generally alternating polycarbonate polyol product.

The product of the first reaction may be fed into the separate reactor containing a pre activated DMC catalyst. The first product may be fed into the separate reactor as a crude reaction mixture.

The first reaction of the present invention may be carried out under CO2 pressure of less than 20 bar, preferably less than 10 bar, more preferably less than 8 bar of CO2 pressure. The second reaction of the present invention may be carried out under CO2 pressure of less than 60 bar, preferably less than 20 bar, more preferably less than 10 bar, most preferably less than 5 bar of CO2 pressure.

The CO2 may be added continuously in the first reaction, preferably in the presence of a starter.

The first reaction may be carried out at a pressure of between about 1 bar and about 60 bar carbon dioxide, optionally about 1 bar and about 40 bar, optionally about 1 bar and about 20 bar, optionally between about 1 bar and about 15 bar, optionally about 1 bar and about 10 bar, optionally about 1 bar and about 5 bar.

The second reaction may be carried out under reduced pressure or an inert gas such as N2 or Ar. Any residual CO2 remaining from the first reaction may be stripped by gas stripping the reaction mixture or by applying a vacuum to the reaction mixture. As discussed above, residual amounts of CO2 may be present in the reaction mixture from the first reaction but will be less than less than 5% CO2 by weight of the reaction mixture prior to addition to the second reaction, preferably less than 2.5%, less than 1.0%, less than 0.5% or less than 0.1%. No additional CO2 is added during the second reaction. The product of the first reaction may be transferred to the second reaction under the pressure of unused CO2 from the first reaction, but no further CO2 is added in the second reactor.

The first reaction process being carried out under these relatively low CO2 pressures and the CO2 added continuously can produce a polyol with high CO2 content, under low pressure. The CO2 may be introduced into the first reactor via standard methods, such as directly into the headspace or directly into the reaction liquid via standard methods such as a inlet tube, gassing ring or a hollow shaft stirrer. The mixing may be optimised by using different configurations of stirrer, such as single agitators or agitators configured in multiple stages.

The first reaction may be carried out in a batch, semi-batch or continuous process. In a batch process, all the carbonate catalyst, epoxide, CO2, starter and optionally solvent are present at the beginning of the reaction. In a semi-batch or continuous reaction, one or more of the carbonate catalyst, epoxide, CO2, starter and/or solvent are added into the reactor in a continuous, semi-continuous or discontinuous manner.

The second reaction comprising DMC may be carried out as a continuous process or a semi-batch process. In a semi-batch or continuous process one or more of the DMC catalyst, epoxide starter and/or solvent is added into the reaction in a continuous or discontinuous manner.

Optionally, the crude reaction mixture fed into the second reactor may include an amount of unreacted epoxide and/or starter.

Optionally, the crude reaction mixture feed may include an amount of carbonate catalyst. Optionally, the carbonate catalyst may have been removed prior to the addition to the second reactor.

The polycarbonate product of the first reaction may be referred to as the crude product.

The polycarbonate product of the first reaction may be fed into the second reaction in a single slug or in a continuous, semi-continuous or discontinuous manner. Preferably, the product of the first reaction is fed into the second reactor in a continuous manner, optionally containing unreacted epoxide and/or carbonate catalyst. This is advantageous as the continuous addition of the product of reaction 1 as a starter for the DMC catalyst allows the DMC catalyst in reactor 2 to operate in a more controlled manner as the ratio of starter to DMC catalyst is always reduced in the reactor. This may prevent deactivation of the DMC catalyst in reactor 2. The polycarbonate of reaction 1 may be fed into the second reactor prior to DMC activation and may be used during the DMC activation. The DMC catalyst may also be pre-activated with the polyol block copolymer which may be added into the reactor, or may be the remaining product from a previous reaction, the so-called‘reaction heel’.

The temperature of the reaction in the first reactor may be in the range of from about 0°C to 250 °C, preferably from about 40 °C to about 160 °C, more preferably from about 50 °C to 120 °C.

The temperature of the reaction in the second reactor may be in the range from about 50 to about 160 °C, preferably in the range from about 70 to about 140 °C, more preferably from about 80 to about 130 °C.

The two reactors may be located in a series, or the reactors may be nested. Each reactor may individually be a stirred tank reactor, a loop reactor, a tube reactor or other standard reactor design.

The first reaction may be carried in more than one reactor that feeds the crude reaction mixture into the second reaction, and reactor, continuously. Preferably, reaction 2 is run in a continuous mode.

The product of the first reaction may be stored for subsequent later use in the second reactor.

Advantageously, the two reactions can be run independently to get optimum conditions for each. If the two reactors are nested they may be effective to provide different reaction conditions to each other simultaneously.

Optionally, the polycarbonate polyol may not have been stabilised by an acid prior to addition to the second reactor.

If the polycarbonate polyol is stabilised by an acid prior to addition to the second reactor, the acid may be an inorganic or an organic acid. Such acids include, but are not limited to, phosphoric acid derivatives, sulfonic acid derivatives (e.g. methanesulfonic acid, p-toluenesulfonic acid), carboxylic acids (e.g. acetic acid, formic acid, oxalic acid, salicylic acid), mineral acids (e.g. hydrochloric acid, hydrobromic acid, hydroiodic acid), nitric acid or carbonic acid. The acid may be part of an acidic resin, such as an ion exchange resin. Acidic ion exchange resins may be in the form of a polymeric matrix (such as polystyrene or polymethacrylic acid) featuring acidic sites such as strong acidic sites (e.g. sulfonic acid sites) or weak acid sites (e.g. carboxylic acid sites). Example ionic exchange resins include Amberlyst 15, Dowex Marathon MSC and Amberlite IRC 748.

The first and second reactions of the present invention may be carried out in the presence of a solvent, however it will also be appreciated that the processes may also be carried out in the absence of a solvent. When a solvent is present, it may be toluene, hexane, t-butyl acetate, diethyl carbonate, dimethyl carbonate, dioxane, dichlorobenzene, methylene chloride, propylene carbonate, ethylene carbonate, acetone, ethyl acetate, propyl acetate, n-butyl acetate, tetrahydrofuran (THF), etc. The solvent may be toluene, hexane, acetone, ethyl acetate and n-butyl acetate.

The solvent may act to dissolve one or more of the materials. However, the solvent may also act as a carrier, and be used to suspend one or more of the materials in a suspension. Solvent may be required to aid addition of one or more of the materials during the steps of the processes of the present invention.

The process may employ a total amount of solvent, and wherein about 1 to 100% of the total amount of solvent may be mixed in the first reaction, with the remainder added in the second reaction; optionally with about 1 to 75% being mixed in the first reaction, optionally with about 1 to 50%, optionally with about 1 to 40%, optionally with about 1 to 30%, optionally with about 1 to 20%, optionally with about 5 to 20%.

The total amount of the carbonate catalyst may be low, such that the first reaction of the invention may be carried out at low catalytic loading. For example, the catalytic loading of the carbonate catalyst may be in the range of about 1 :500-100,000 [total carbonate catalyst]: [total epoxide], such as about 1 :750-50,000 [total carbonate catalyst]:[ total epoxide], e.g. in the region of about 1 :1 ,000-20,000 [total carbonate catalyst]:[ total epoxide], for example in the region of about 1 :10,000 [total carbonate catalyst]:[ total epoxide]. The ratios above are molar ratios. These ratios are the ratios of the total amount of carbonate catalyst to the total amount of epoxide used in the first reaction.

The process may employ a total amount of epoxide, and about 1 to 100% of the total amount of epoxide may be mixed in the first reaction. The remainder of epoxide may be added in the second reaction; with optionally about 5 to 90% being mixed in the first reaction, optionally with about 10 to 90%, optionally with about 20 to 90%, optionally with about 40 to 90%, optionally with about 40 to 80%, optionally with about 5 to 50%.

The epoxide which is used in the first and second reactions may be any suitable compound containing an epoxide moiety. Exemplary epoxides include ethylene oxide, propylene oxide, butylene oxide and cyclohexene oxide. The epoxide(s) used for the second reaction may be the same or different from the epoxide(s) used for the first reaction. Accordingly, a mixture of one or more epoxides may be present in one or both of the reactions. For example, the first reaction may comprise propylene oxide and the second reaction may comprise ethylene

oxide, or both reactions may comprise ethylene oxide, or one or both reactions may use a mixture of epoxides such as a mixture of ethylene oxide with propylene oxide.

The epoxide may be purified (for example by distillation, such as over calcium hydride) prior to reaction with carbon dioxide. For example, the epoxide may be distilled prior to being added.

Examples of epoxides which may be used in the present invention include, but are not limited to, cyclohexene oxide, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, substituted cyclohexene oxides (such as limonene oxide, C10H16O or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, C1 1H22O), alkylene oxides (such as ethylene oxide and substituted ethylene oxides), unsubstituted or substituted oxiranes (such as oxirane, epichlorohydrin, 2-(2-methoxyethoxy)methyl oxirane (MEMO), 2-(2-(2-methoxyethoxy)ethoxy)methyl oxirane (ME2MO), 2-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)methyl oxirane (ME3MO), 1 ,2-epoxybutane, glycidyl ethers, glycidyl ester, glycidyl carbonates, vinyl-cyclohexene oxide, 3-phenyl-1 , 2-epoxypropane, 2,3-epoxybutane, isobutylene oxide, cyclopentene oxide, 2,3-epoxy-1 ,2,3,4-tetrahydronaphthalene, indene oxide, and functionalized 3,5-dioxaepoxides. Examples of functionalized 3,5-dioxaepoxides include:

The epoxide moiety may be a glycidyl ether, glycidyl ester or glycidyl carbonate. Examples of glycidyl ethers, glycidyl esters glycidyl carbonates include:

As noted above, the epoxide substrate may contain more than one epoxide moiety, i.e. it may be a bis-epoxide, a tris-epoxide, or a multi-epoxide containing moiety. Examples of compounds including more than one epoxide moiety include, bis-epoxybutane, bis-epoxyoctane, bis-epoxydecane, bisphenoi A digiyddy! ether and 3,4-epoxycyclohexylmethyl-3’,4’-epoxycyclohexanecarboxylate. It will be understood that reactions carried out in the presence of one or more compounds having more than one epoxide moiety may lead to cross-linking in the resulting polymer.

Optionally, between 0.1 and 20% of the total epoxide in the first reaction may be an epoxide substrate containing more than one epoxide moiety. Preferably, the multi-epoxide substrate is a bis-epoxide.

The skilled person will appreciate that the epoxide can be obtained from “green” or renewable resources. The epoxide may be obtained from a (poly)unsaturated compound, such as those deriving from a fatty acid and/or terpene, obtained using standard oxidation chemistries.

The epoxide moiety may contain -OH moieties, or protected -OH moieties. The -OH moieties may be protected by any suitable protecting group. Suitable protecting groups include methyl or other alkyl groups, benzyl, allyl, tert-butyl, tetrahydropyranyl (THP), methoxymethyl (MOM), acetyl (C(O)alkyl), benzolyl (C(O)Ph), dimethoxytrityl (DMT), methoxyethoxymethyl (MEM), p-methoxybenzyl (PMB), trityl, silyl (such as trimethylsilyl (TMS), f-butyldimethylsilyl (TBDMS), f-butyldiphenylsilyl (TBDPS), tri-/so-propylsilyloxymethyl (TOM), and triisopropyisiiyi (TIPS)), (4-methoxyphenyl)dipheny!methyl (MMT), tetrahydrofuranyl (THF), and tetrahydropyranyl (THP).

The epoxide optionally has a purity of at least 98%, optionally >99%.

The rate at which the materials are added may be selected such that the temperature of the (exothermic) reactions does not exceed a selected temperature (i.e. that the materials are added slowly enough to allow any excess heat to dissipate such that the temperature of the remains approximately constant). The rate at which the materials are added may be selected such that the epoxide concentration does not exceed a selected epoxide concentration.

The process may produce a polyol with a polydispersity between 1.0 and 2.0, preferably between 1.0 and 1.8, more preferably between 1.0 and 1.5, most preferably between 1.0 and 1.3.

The process may comprise mixing double metal cyanide (DMC) catalyst, epoxide, starter and optionally solvent to form a pre-activated mixture and adding the pre-activated mixture to the second reactor either before or after the crude reaction mixture of the first reaction, to form the second reaction mixture. However, this may take place continuously so that the pre activated mixture is added at the same time as the crude reaction mixture. The pre-activated mixture may also be formed in the second reactor by mixing the DMC catalyst, epoxide, starter and optionally solvent. The pre-activation may occur at a temperature of about 50 °C to 160 °C, preferably between about 70°C to 140 °C, more preferably about 90 °C to 140 °C.The pre-activated mixture may be mixed at a temperature of between about 50 to 160 °C prior to contact with the crude reaction mixture, optionally between about 70 to 140 °C.

In the overall reaction process, the amount of said carbonate catalyst and the amount of said double metal cyanide (DMC) catalyst may be at a predetermined weight ratio of from about 300:1 to about 1 :100 to one another, for example, from about 120:1 to about 1 :75, such as from about 40:1 to about 1 :50, e.g. from about 30:1 to about 1 :30 such as from about 20:1 to about 1 :1 , for example from about 10:1 to about 2:1 , e.g. from about 5:1 to about 1 :5. The processes of the present invention can be carried out on any scale. The process may be carried out on an industrial scale. As will be understood by the skilled person, catalytic reactions are generally exothermic. The generation of heat during a small-scale reaction is unlikely to be problematic, as any increase in temperature can be controlled relatively easily by, for example, the use of an ice bath. With larger scale reactions, and particularly industrial scale reactions, the generation of heat during a reaction can be problematic and potentially dangerous. Thus, the gradual addition of materials may allow the rate of the catalytic reaction to be controlled and can minimise the build-up of excess heat. The rate of the reaction may be controlled, for example, by adjusting the flow rate of the materials during addition. Thus, the processes of the present invention have particular advantages if applied to large, industrial scale catalytic reactions.

The temperature may increase or decrease during the course of the processes of the invention.

The amount of said carbonate catalyst and the amount of said double metal cyanide (DMC) catalyst will vary depending on which carbonate catalyst and DMC catalyst is used.

The product of the process of the first aspect of the invention is a polyol block copolymer. According to the third aspect of the invention, there is provided a polyol block copolymer comprising a polycarbonate block, A (-A’-Z’-Z-(Z’-A’)n-), and polyether blocks, B, wherein the polyol block copolymer has the polyblock structure:

B-A’-Z’-Z-(Z’-A’-B)n

wherein n= t-1 and wherein t= the number of terminal OH group residues on the block A; and wherein each A’ is independently a polycarbonate chain having at least 70% carbonate linkages, and wherein each B is independently a polyether chain and wherein Z’-Z-(Z’)n is a starter residue.

In the process according to the first aspect, the starter may be a monofunctional starter. In that case, for the avoidance of doubt, the polyblock structure is>

B-A’-Z’-Z

The polycarbonate block comprises -A’- which may have the following structure:

wherein the ratio of p:q is at least 7:3; and

Re1 and Re2 depend on the nature of the epoxide used to prepare blocks A.

The polyether block B may have the following structure:

wherein

Re3 and Re4 depend on the nature of the epoxide used to prepare blocks B.

Each Re1 , Re2, Re3, or Re4 may be independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl, preferably selected from H or optionally substituted alkyl.

Re1 and Re2 or Re3 and Re4 may together form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms, and optionally one or more heteroatoms.

WE CLAIMS

1. A process for producing a polyol block copolymer in a multiple reactor system; the system comprising a first and second reactor wherein a first reaction takes place in the first reactor and a second reaction takes place in the second reactor; wherein the first reaction is the reaction of a carbonate catalyst with CO2 and epoxide, in the presence of a starter and/or solvent to produce a polycarbonate polyol copolymer and the second reaction is the reaction of a DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce a polyol block copolymer, wherein (i) the product of the first reaction is fed into the second reactor as a crude reaction mixture, (ii) the epoxide and the polycarbonate polyol compound of the first reaction are fed into the second reactor in a continuous or semi-batch manner, and/or (iii) the product of the first reaction has a neutral or alkaline pH on addition to the second reaction.

2. A process for producing a polyol block copolymer in a multiple reactor system; the system comprising a first and second reactor wherein a first reaction takes place in the first reactor and a second reaction takes place in the second reactor; wherein the first reaction is the reaction of a carbonate catalyst with CO2 and epoxide, in the presence of a polyfunctional starter, and optionally a solvent, to produce a polycarbonate polyol and the second reaction is the semi-batch or continuous reaction of a DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce a polyol block copolymer.

3. A process for producing a polyol block copolymer according to claim 2, wherein the starter compound has the formula (III):

Z-f Rz)a (III)

wherein Z can be any group which can have 2 or more -Rz groups attached to it and may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene, heteroalkylheteroarylene or alkylheteroarylene group;

a is an integer which is at least 2, optionally a is in the range of between 2 and 8, optionally a is in the range of between 2 and 6;

wherein each Rz may be -OH, -NHR’, -SH, -C(0)OH, -P(0)(OR’)(OH), -PR’(0)(OH)2 or -PR’(0)OH, optionally Rz is selected from -OH, -NHR’ or -C(0)OH, optionally each Rz is -OH, -C(0)OH or a combination thereof (e.g. each Rz is -OH);

wherein R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, optionally R’ is H or optionally substituted alkyl.

4. A process according to any preceding claim, wherein the DMC catalyst is pre-activated, optionally in the second reactor or separately, optionally wherein the DMC is pre-activated with a starter compound or with the reaction product of the first or second reaction or with a polycarbonate polyol copolymer or with a polyol block copolymer.

5. A process according to any preceding claim, wherein the polycarbonate polyol copolymer is added to pre-activated DMC catalyst.

6. A process according to any preceding claim, wherein the DMC catalyst is pre-activated with a starter compound, or the polycarbonate polyol copolymer, or with the polyol block copolymer product.

7. A process according to any preceding claim, wherein the product of the first reaction is a low molecular weight polycarbonate polyol product having a molecular weight (Mn) in the range 200 to 4000 Daltons as measured by Gel Permeation Chromatography (GPC).

8. A process according to any preceding claim, wherein the first reaction produces a generally alternating polycarbonate polyol product.

9. A process according to any preceding claim wherein the epoxide is asymmetric and wherein the reaction produces a polycarbonate having

between 40-100% head to tail linkages, preferably more than 70%, more than 80% or more than 90% head to tail linkages.

10. A process according to any preceding claim, wherein the product of the first reaction is fed into the second reactor, as a crude reaction mixture, wherein said second reactor contains a pre-activated DMC catalyst.

11. A process according to any preceding claim, wherein the polycarbonate copolymer is fed into the reaction with the DMC catalyst, as a crude reaction mixture, wherein said reaction contains a pre-activated DMC catalyst.

12. A process according to any preceding claim, wherein the first reaction is carried out under CO2 pressure of less than 20 bar, more preferably, less than

10 bar, most preferably, less than 8 bar.

13. A process according to any preceding claim, wherein the CO2 is added continuously in the first reaction.

14. A process according to any preceding claim, wherein the first reaction is a batch, semi-batch, or continuous process.

15. A process according to any preceding claim, wherein the second reaction is a continuous process or semi batch process.

16. A process according to any preceding claim, wherein the crude reaction mixture fed into the second reactor includes an amount of unreacted epoxide and/or starter.

17. A process according to any preceding claim, wherein the carbonate catalyst is present in the crude reaction mixture.

18. A process according to any preceding claim, wherein the carbonate catalyst has been removed from the crude reaction mixture prior to the addition to the second reactor.

19. A process according to any preceding claim, wherein the temperature of reaction in the first reactor is in the range about 0°C to 250 °C, preferably from about 40 °C to about 160 °C, more preferably from about 50 °C to 120 °C

20. A process according to any preceding claim, wherein the temperature of reaction in the second reactor is in the range from about 50 to about 160°C, preferably in the range from about 70 to about 140°C, more preferably from about 80 to about 130°C.

21. A process according to any preceding claim, wherein the reactors are located in series.

22. A process according to any of claims 1 -20, wherein the reactors are nested.

23. A process according to any preceding claim, wherein the first and second reactors are effective to provide different reaction conditions, such as temperature and/or pressure, to each other simultaneously.

24. A process according to any preceding claim, wherein the process employs a total amount of epoxide, and wherein about 1 to 100% of the total amount of epoxide is mixed in the first reaction, with any remainder added in the second reaction; optionally with about 5 to 90% being mixed in the first reaction, optionally with about 10 to 90%, optionally with about 20 to 90%, optionally with about 40 to 90%, optionally with about 40 to 80%, optionally with about 5 to 50%.

25. A process according to any preceding claim, wherein the epoxides are selected from cyclohexene oxide, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, substituted cyclohexene oxides (such as limonene oxide, C10H16O or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, C11H22O), alkylene oxides (such as ethylene oxide and substituted ethylene oxides), unsubstituted or substituted oxiranes (such as oxirane, epichlorohydrin, 2-(2-methoxyethoxy)methyl oxirane (MEMO), 2-(2-(2-methoxyethoxy)ethoxy)methyl oxirane (ME2MO), 2-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)methyl oxirane (ME3MO), 1 ,2-epoxybutane, glycidyl ethers, glycidyl esters, glycidyl carbonates, vinyl-cyclohexene oxide, 3-phenyl-1 ,2-epoxypropane, 2,3-epoxybutane, isobutylene oxide, cyclopentene oxide, 2,3-epoxy-1 ,2,3,4-tetrahydronaphthalene, indene oxide, and functionalized 3,5-dioxaepoxides. 26. A process according to any preceding claim, wherein between 0.1 and 20% of the total epoxide in the first reaction is an epoxide substrate containing more than one epoxide moiety, preferably a bis-epoxide.

27. A process according to any preceding claim wherein the carbonate catalyst is a catalyst capable of producing polycarbonate chains with greater than 76% carbonate linkages.

28. A process according to any preceding claim, wherein the carbonate catalyst is a metal catalyst comprising phenol or phenolate ligands.

29. A process according to any preceding claim, wherein the carbonate catalyst is a bimetallic complex comprising phenol or phenolate ligands.

30. A process according to any preceding claim wherein the carbonate catalyst is a catalyst of Formula (IV):

Wherein M is a metal cation represented by M-(L)V;

x is an integer from 1 to 4,

a multidentate ligand or plurality of multidentate ligands;

L is a coordinating ligand;

v is an integer that satisfies the valency of M, and/or the preferred coordination geometry of M or is such that the complex represented by formula (IV) above has an overall neutral charge.

31. A process according to any preceding claim, wherein the carbonate catalyst has the following structure:

wherein Mi and M2 are independently selected from Zn(ll), Cr(ll), Co(ll), Cu(ll), Mn(ll), Mg(ll), Ni(ll), Fe(ll), Ti(ll), V(ll), Cr(lll)-X, Co(lll)-X, Mn(lll)-X, Ni(lll)-X, Fe(lll)-X, Ca(ll), Ge(ll), Al(lll)-X, Ti(lll)-X, V(lll)-X, Ge(IV)-(X)2 or Ti(IV)-(X)2; Ri and R2 are independently selected from hydrogen, halide, a nitro group, a nitrile group, an imine, an amine, an ether group, a silyl group, a silyl ether group, a sulfoxide group, a sulfonyl group, a sulfinate group or an acetylide group or an optionally substituted alkyl, alkenyl, alkynyl, haloalkyl, aryl, heteroaryl, alkoxy, aryloxy, alkylthio, arylthio, alicyclic or heteroalicyclic group; R3 is independently selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene, heteroarylene or cycloalkylene, wherein alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene and heteroalkynylene, may optionally be interrupted by aryl, heteroaryl, alicyclic or heteroalicyclic;

R5 is independently selected from FI, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl or alkylaryl;

Ei is C, E2 is O, S or NH or Ei is N and E2 is O;

E3, E4, E5 and Eb are selected from N, NR4, 0 and S, wherein when E3, E4, E5 or Eb are N, - is , and wherein when E3, E4, E5 or Eb are NR4, 0 or

S, - is - ;

R4 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl, -alkylC(0)ORi9 or -alkylCºN or alkylaryl;

X is independently selected from OC(0)Rx, OSC^Rx, OSORx, OSO(Rx)2, S(0)Rx, ORx, phosphinate, halide, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, wherein each X may be the same or different and wherein X may form a bridge between Mi and M2;

Rx is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl; and

G is absent or independently selected from a neutral or anionic donor ligand which is a Lewis base.

32. A process according to any of claims 1 -30 wherein the carbonate catalyst is selected from catalysts of formula (IV), metal salen catalysts, metal porphyrin catalysts, metal tetraaza annulene catalysts and metal beta-diiminate catalysts as defined herein.

33. A process according to any preceding claim, wherein the DMC catalyst, in addition to at least two metal centres and cyanide ligands, also comprises at least one of: one or more complexing agents, water, a metal salt and/or an acid, optionally in non-stoichiometric amounts.

34. A process according to any preceding claim, wherein the DMC catalyst is prepared by treating a solution of a metal salt with a solution of a metal cyanide salt in the presence of at least one of: complexing agent, water, and/or an acid, optionally wherein the metal salt is of the formula M’(X’)P, wherein M’ is selected from Zn(ll), Ru(ll), Ru(lll), Fe(ll), Ni(ll), Mn(ll), Co(ll), Sn(ll), Pb(ll), Fe(lll), Mo(IV), Mo(VI), Al(lll), V(V), V(VI), Sr(ll), W(IV), W(VI), Cu(ll), and Cr(lll),

X’ is an anion selected from halide, oxide, hydroxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate,

p is an integer of 1 or more, and the charge on the anion multiplied by p satisfies the valency of M’; the metal cyanide salt is of the formula (Y)qM”(CN)b(A)c, wherein M” is selected from Fe(ll), Fe(lll), Co(ll), Co(lll), Cr(ll), Cr(lll), Mn(ll), Mn(lll), Ir(lll), Ni(ll), Rh(lll), Ru(ll), V(IV), and V(V),

Y is a proton or an alkali metal ion or an alkaline earth metal ion (such as K+),

A is an anion selected from halide, oxide, hydroxide, sulphate, cyanide oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate;

q and b are integers of 1 or more;

c may be 0 or an integer of 1 or more;

the sum of the charges on the anions Y, CN and A multiplied by q, b and c respectively (e.g. Y x q + CN x b + A x c) satisfies the valency of M”;

the at least one complexing agent is selected from a (poly)ether, a polyether carbonate, a polycarbonate, a poly(tetramethylene ether diol), a ketone, an ester, an amide, an alcohol, a urea or a combination thereof,

optionally wherein the at least one complexing agent is selected from propylene glycol, polypropylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol and sec-butyl alcohol, 3-buten-1 -ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1 -pentyn-3-ol, or a combination thereof; and

wherein the acid, if present, has the formula HrX’”, where X’” is an anion selected from halide, sulfate, phosphate, borate, chlorate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, and r is an integer corresponding to the charge on the counterion X’”.

35. A process according to any preceding claim, wherein the DMC catalyst comprises the formula:

M’d[M”e(CN)f]g

wherein M’ and M” are as defined in claim 29, and d, e, f and g are integers, and are chosen such that the DMC catalyst has electroneutrality,

optionally, d is 3, e is 1 , f is 6 and g is 2.

36. A process according to any preceding claim, wherein the DMC catalyst comprises the formula:

M’d[M”e(CN)f]g hM”’X”i jRc kH20 IHrX’” wherein M’, M”, d, e, f and g are as defined in claim 29, M’” is M’ and/or M”, X” is an anion selected from halide, oxide, hydroxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, i is an integer of 1 or more, and the charge on the anion X” multiplied by i satisfies the valency of M’”, h, j, k and I are each independently zero or a positive number, r is an integer that corresponds to the charge on the counterion X’”, and Rc is a complexing agent or a combination of one or more complexing agents.

37. A process according to any preceding claim, wherein the DMC catalyst is based upon Zn3[Co(CN)6]2 (zinc hexacyanocobaltate).

38. A process according to any preceding claim, wherein the DMC catalyst is zinc hexacyanocobaltate and the one or more ligands are selected from alcohols and polyols.

39. A process according to claim 34, wherein the one or more complexing agents are selected from dimethoxyethane, tert-butyl alcohol, polyethylene glycol, polypropylene glycol, polyethercarbonate, poly(tetramethylene glycol), polycarbonate.

40. A process according to any preceding claim wherein the product of the first reaction is fed into the second reactor in a single slug or in a continuous or discontinuous manner, preferably in a continuous manner.

41. A process according to any preceding claim wherein the product of the first reaction is used to pre-activate the DMC catalyst in the second reaction, prior to addition of epoxide.

42. A process according to any preceding claim, wherein the same or different epoxides are used in the first or second reactions.

43. A process according to any preceding claim, wherein the epoxide used in the first or second reaction comprises propylene oxide, ethylene oxide or a mixture of propylene oxide and ethylene oxide.

44. A process according to any preceding claim, wherein the epoxide used in the second reactor is propylene oxide.

45. A process according to any preceding claim, wherein the second reaction is carried substantially in the absence of CO2.

46. A process according to any preceding claim, wherein the polyol block copolymer produced in the second reaction is a polycarbonate block polyether polyol block copolymer.

47. A polyol block copolymer comprising a polycarbonate block, A (-A’-Z’-Z-(Z’-A’)n-), and polyether blocks, B, wherein the polyol block copolymer has the polyblock structure:

B - A -Z’ -Z-(Z’ - A - B ) n

wherein n= t-1 and wherein t= the number of terminal OH group residues on the block A; and t = at least 2; and

wherein each A is independently a polycarbonate chain having at least 70% carbonate linkages, and wherein each B is independently a polyether chain; and wherein Z’-Z-(Z’)n is a starter residue.

48. A polyol block copolymer according to claim 47, wherein -A- has the following structure:

wherein the ratio of p:q is at least 7:3;

and block B has the following structure:

and Re1, Re2, Re3 and Re4 depend on the nature of the epoxide used to prepare blocks A and B.

49. A polyol block copolymer according to claim 47 or 48, wherein each Re1 , Re2, Re3, or Re4 is independently selected from H, halogen, hydroxyl, or optionally substituted alkyl (such as methyl, ethyl, propyl, butyl, -CH2CI, -CH2-OR20, - CH2-0C(0)Ri2, or -CH2-0C(0)0Ri8), alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl, preferably selected from H or optionally substituted alkyl.

50. A polyol block copolymer according to any of claims 47-49, wherein Re1 and Re2 or Re3 and Re4 together form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms, and optionally one or more heteroatoms.

51. A polyol block copolymer according to any of claims 47-50, wherein the starter residue depends on the nature of the starter compound, and wherein the starter compound has the formula (III):

Z-f Rz)a (III)

wherein Z can be any group which can have 2 or more -Rz groups attached to it and may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene,

cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene,

heteroalkylheteroarylene or alkylheteroarylene group;

a is an integer which is at least 2, optionally a is in the range of between 2 and 8, optionally a is in the range of between 2 and 6;

wherein each Rz may be -OH, -NHR’, -SH, -C(0)OH, -P(0)(OR’)(OH), - PR’(0)(OH)2 or -PR’(0)OH, optionally RZ is selected from -OH, -NHR’ or - C(0)OH, optionally each Rz is -OH, -C(0)OH or a combination thereof (e.g. each Rz is -OH);

wherein R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, optionally R’ is H or optionally substituted alkyl; and

wherein Z’ corresponds to Rz, except that a bond replaces the labile hydrogen atom.

52. A polyol block copolymer according to claim 51 , wherein the starter compound is selected from diols such as 1 ,2-ethanediol (ethylene glycol), 1 - 3-propanediol, 1 ,2-butanediol, 1-3-butanediol, 1 ,4-butanediol, 1 ,5- pentanediol, 1 ,6-hexanediol, 1 ,8-octanediol, 1 ,10-decanediol, 1 ,12- dodecanediol, 1 ,4-cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425, PPG 725, PPG 1000 and the like, triols such as glycerol, benzenetriol, 1 ,2,4-butanetriol, 1 ,2,6-hexanetriol, tris(methylalcohol)propane, tris(methylalcohol)ethane, tris(methylalcohol)nitropropane, trimethylol propane, polyethylene oxide triols, polypropylene oxide triols and polyester triols, tetraols such as calix[4]arene, 2,2-bis(methylalcohol)-1 ,3-propanediol, erythritol, pentaerythritol or polyalkylene glycols (PEGs or PPGs) having 4-OH groups, polyols, such as sorbitol or polyalkylene glycols (PEGs or PPGs) having 5 or more -OH groups, or compounds having mixed functional groups including ethanolamine, diethanolamine, methyldiethanolamine, and phenyldiethanolamine.

53. A polyol block copolymer according to any of claims 47-52, wherein the polyol molecular weight (Mn) is in the range 300-20,000 Da and the

molecular weight (Mn) of block A is in the range 200-4000 Da, and wherein the molecular weight (Mn) of block B is in the range 100-20,000 Da, more typically, the molecular weight (Mn) of block A is 200-2000 Da , more typically 200-1000 Da, most typically 400-800 Da and/or the molecular weight (Mn)of block B is typically 200-10,000 Da, more typically 200-5000 Da.

54. A polyol block copolymer according to claim 53, wherein the molecular weight (Mn) is measured by Gel Permeation Chromatography (GPC).

55. A polyol block copolymer according to any of claims 47-54, wherein block A has at least 76%, more typically, at least 80% or most typically at least 85% carbonate linkages.

56. A polyol block copolymer according to any of claims 47-55, wherein block A has less than 98% carbonate linkages, more typically, less than 97% carbonate linkages or most typically less than 95% carbonate linkages.

57. A polyol block copolymer according to any of claims 47-56, wherein block A has between 75% and 99% carbonate linkages, more typically, between 77% and 95% carbonate linkages, most typically between 80 and 90% carbonate linkages.

58. A polyol block copolymer according to any of claims 47-57, wherein block B has less than 1 % carbonate linkages.

59. A polyol block copolymer according to any of claims 47-58, wherein block A further comprises ether linkages.

60. A polyol block copolymer according to claim 59, wherein block A has less than 24% ether linkages, more typically, less than 20% ether linkages, most typically, less than 15% ether linkages.

61. A polyol block copolymer according to claims 59 or 60, wherein block A has at least 1 % ether linkages, more typically, at least 3% ether linkages, most typically, at least 5% ether linkages.

62. A polyol block copolymer according to any of claims 59-61 , wherein block A has between 1 % and 25% ether linkages, typically between 5% and 20% ether linkages, more typically, between 10% and 15% ether linkages.

63. A polyol block copolymer according to any of claims 59-62 wherein the epoxide is asymmetric and the polycarbonate has between 40-100% head to tail linkages, preferably more than 50% head to tail linkages.

64. A polyol block copolymer according to any of claims 59-62 wherein between 0.1 and 20% of the total epoxide in block A is an epoxide substrate containing more than one epoxide moiety, preferably a bis-epoxide.

65. A polyol block copolymer according to any of claims 47-64, wherein block A is a generally alternating polycarbonate polyol residue.

66. A polyol block copolymer according to any of claims 47-65, wherein the mol/mol ratio of block A to block B is in the range 25:1 to 1 :250.

67. A polyol block copolymer according to any of claims 47-66, wherein at least 30% of the epoxide residues of block A are ethylene oxide or propylene oxide residues, typically, at least 50% of the epoxide residues of block A are ethylene oxide or propylene oxide residues, more typically, at least 75% of the epoxide residues of block A are ethylene oxide or propylene oxide residues, most typically, at least 90% of the epoxide residues of block A are ethylene oxide or propylene oxide residues.

68. A polyol block copolymer according to any of claims to 47-67, wherein at least 30% of the epoxide residues of block B are ethylene oxide or propylene oxide residues, typically, at least 50% of the epoxide residues of block B are ethylene oxide or propylene oxide residues, more typically, at least 75% of the epoxide residues of block B are ethylene oxide or propylene oxide residues, most typically, at least 90% of the epoxide residues of block B are ethylene oxide or propylene oxide residues.

69. A process according to any of claims 1 -46, wherein the polyol block copolymer produced in the second reaction is according to any of claims 47- 68.

70. A polyurethane produced from the reaction of a polyol block copolymer produced according to the process of any of claims 1 to 46 and a (poly)isocyanate.

71. A polyurethane comprising a block copolymer residue having a polycarbonate block, A (-A’-Z’-Z-(Z’-A’)n-), wherein A is a polycarbonate chain having at least 70% carbonate linkages, and polyether blocks, B, wherein the residue has a polyblock structure B-A’-Z’-Z-(Z’-A-B)n, wherein n= t-1 and wherein t= the number of terminal OH group residues on the block A and wherein Z’-Z-(Z’)n is a starter residue.

72. A polyurethane according to claim 71 , wherein the residue includes any one or more of the features defined in claims 47-68.

73. An isocyanate terminated polyurethane prepolymer comprising the reaction product of a block copolymer prepared according to the process of any of claims 1 to 47 with an excess of (poly)isocyanate.

74. An isocyanate terminated polyurethane prepolymer comprising a block copolymer residue having a polycarbonate block, A (-A’-Z’-Z-(Z’-A’)n-), wherein A is a polycarbonate chain having at least 70% carbonate linkages and polyether blocks, B, each having up to 50% carbonate linkages and at least 50% ether linkages wherein the residue has a polyblock structure B-A’-Z’-Z-(Z’- A-B)n, wherein n= t-1 and wherein t= the number of terminal OH group residues on the block A and wherein Z’-Z-(Z’)n is a starter residue.

75. An isocyanate terminated polyurethane prepolymer according to claim 74, wherein the residue includes any one or more of the features defined in claims 47-68.

76. A polyurethane according to of any of claims 70-72, wherein the polyurethane is in the form of a soft foam, a flexible foam, an integral skin foam, a high resilience foam, a viscoelastic or memory foam, a semi-rigid foam, a rigid foam (such as a polyurethane (PUR) foam, a polyisocyanurate (PIR) foam and/or a spray foam), an elastomer (such as a cast elastomer, a thermoplastic elastomer (TPU) or a microcellular elastomer), an adhesive (such as a hot melt adhesive, pressure sensitive or a reactive adhesive), a sealant or a coating (such as a waterborne or solvent dispersion (PUD), a two- component coating, a one component coating, a solvent free coating).

77. A polyurethane according to claim 76, wherein the polyurethane is formed via a process that involves extruding, moulding, injection moulding, spraying, foaming, casting and/or curing.

78. A polyurethane according to claim 76 or 77, wherein the polyurethane is formed via a‘one pot’ or‘pre-polymer’ process.

79. A composition comprising the polyol block copolymer of any of claims 47-68 and one or more additives selected from catalysts, blowing agents, stabilizers, plasticisers, fillers, flame retardants, and antioxidants.

80. A composition according to claim 80 further comprising a (poly)isocyanate.

81. A composition according to claim 80 or 81 , wherein the catalysts for the (poly)isocyanate and the polyol block copolymer reaction include suitable urethane catalysts such as tertiary amine compounds and/or organometallic compounds.

82. A composition according to claim 81 or 82, wherein a trimerisation catalyst is present.

83. A composition according to claim 81 , wherein an excess of (poly)isocyanate, more typically, an excess of polymeric isocyanate relative to polyol is present so that polyisocyanurate ring formation in the presence of the trimerisation catalyst is possible.

84. A lubricant composition comprising a polyol block copolymer of any of claims 47-68.

85. A surfactant composition comprising a polyol block copolymer of any of claims 47-68.