Description:CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[0001] The present application does not claim priority from any other patent application.
TECHNICAL FIELD
[0002] The present disclosure pertains to the field of natural rubber production and processing, and more specifically, to a method for extracting and processing latex from non-Hevea plant, particularly Cryptostegia grandiflora, and product thereof.
BACKGROUND
[0003] Natural rubber is a high-performance, elastomeric biopolymer composed primarily of cis-1,4-polyisoprene units, which confer its exceptional mechanical and dynamic properties. Predominantly sourced from the latex of Hevea brasiliensis, this renewable material is critical to a wide array of industrial, commercial, and medical applications. Its intrinsic characteristics, such as high resilience, elongation at break, tensile strength, tear resistance, and fatigue durability, make it indispensable in the production of pneumatic tires, automotive components, vibration dampers, engineering seals, footwear, and surgical equipment.
[0004] The conventional production of natural rubber involves the exudation of latex from Hevea brasiliensis through controlled bark incision or “tapping,” which yields a colloidal suspension of rubber particles in an aqueous serum. The harvested latex undergoes coagulation using chemical coagulants - low molecular weight organic acids such as acetic acid or formic acid, as well as selected organic solvents like acetone. Subsequent processing steps include washing, drying, and purification to isolate the solid rubber phase and remove residual non-rubber constituents. Over the decades, coagulation protocols have been refined to maximize dry rubber yield, reduce volatile extractables, and enhance the physicochemical consistency of the final rubber product. Nevertheless, this production framework remains intrinsically dependent on the agronomic health and biological productivity of Hevea plantations.
[0005] Despite its commercial significance, the global natural rubber industry faces increasing challenges due to its predominant reliance on Hevea brasiliensis as the primary latex source. Hevea plantations are highly susceptible to a wide array of phytopathogenic stresses that substantially impair latex yield. Fungal pathogens such as Corynespora cisticola cause leaf diseases leading to defoliation and diminished photosynthetic capacity, while stem infections, including pink disease, and panel afflictions such as black stripe, contribute to bark degradation and reduced latex flow. Additionally, root diseases further compromise tree vigor, collectively reducing the productivity and lifespan of rubber trees. These biotic pressures, compounded by various abiotic stressors, increasingly threaten the sustainability and resilience of natural rubber production.
[0006] Moreover, latex tapping in Hevea is restricted to specific climatic windows, as periods of heavy monsoonal rainfall and excessive heat either physically prevent tapping or reduce latex flow due to plant stress. This seasonality directly affects supply consistency. Additionally, Hevea cultivation demands narrowly defined pedoclimatic conditions, specifically deep, well-aerated soils with high organic content and continuous soil moisture. Such geographic and environmental specificity significantly limits the expansion of rubber plantations beyond traditional tropical regions. These agro-environmental challenges are further compounded by systemic socio-economic limitations, including insufficient infrastructure for latex collection and processing, inconsistent market access, and fluctuating profitability. Consequently, many smallholder farmers are transitioning away from rubber cultivation, further contributing to the declining availability of natural rubber in global markets.
[0007] Additionally, latex derived from Hevea typically contains significant amounts of residual proteins, which remain in the final rubber product even after standard purification. These proteins are known to cause adverse effects in humans, including allergic reactions and skin irritation upon prolonged exposure
[0008] In light of the aforementioned limitations, there has been a growing interest in exploring alternative botanical sources capable of producing natural rubber with properties analogous to those obtained from Hevea brasiliensis. One such candidate is Cryptostegia grandiflora (Crypto), a non-Hevea species (plant species that do not belong to the Hevea genus) that synthesizes latex with inherent rubber-like elasticity. This plant species exhibits improved resistance to environmental stressors such as temperature extremes and drought and shows reduced susceptibility to common latex-yield-limiting pathogens affecting Hevea, making it an ecologically and agronomically robust alternative for rubber production.
[0009] However, the physico-chemical characteristics of latex derived from Cryptostegia grandiflora differ significantly from Hevea latex in terms of composition, emulsification behavior, and coagulation response. Consequently, conventional processing methodologies—optimized primarily for Hevea—do not yield satisfactory results when applied to Cryptostegia latex. This discrepancy underscores the critical need for the development of specialized protocols tailored specifically to Cryptostegia, encompassing customized extraction methods, coagulation chemistry, and stabilization processes. Such innovations are essential to realizing the full potential of Cryptostegia grandiflora as a commercially viable and sustainable alternative to traditional Hevea-based rubber production systems.
[0010] Furthermore, the high concentration of coagulating agents required for effective latex processing presents an additional challenge. This increased demand for coagulants not only raises processing costs but also introduces potential environmental and material compatibility concerns. As such, there exists a requirement to reduce the amount of coagulating agent necessary for efficient coagulation of Cryptostegia grandiflora latex, while still achieving acceptable yield and material properties.
[0011] The present disclosure addresses these challenges by introducing a scalable method for extracting and processing latex from Cryptostegia grandiflora, offering a commercially viable solution to overcome the limitations of the traditional Hevea rubber supply.
[0012] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of described systems with some aspects of the present disclosure, as set forth in the remainder of the present application and with reference to the drawings.
SUMMARY
[0013] This summary is provided to introduce concepts related to a method for extracting and processing latex from non-Hevea plants, particularly Cryptostegia grandiflora, and product thereof. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
[0014] An aspect of the instant disclosure relates to a method for extracting and processing latex from a plant, the method comprising, collecting latex from the plant via tapping; carrying out coagulation, wherein the coagulation is carried out chemically or mechanically to obtain a coagulated rubber mass; separating the coagulated rubber mass from liquid phase; washing the coagulated rubber mass with water; and drying the coagulated rubber mass to obtain dry rubber, wherein the plant is a non-Hevea plant.
[0015] A related aspect of the instant disclosure relates to a method for producing an elastomer, the method comprising compounding and mixing the dry rubber with zinc oxide, stearic acid, sulfur, carbon black, antioxidants, and a vulcanization accelerator via milling to obtain a compounded rubber; and molding and vulcanizing the compounded rubber to obtain the elastomer.
[0016] Another aspect of the instant disclosure relates to an elastomer comprising a dry rubber; zinc oxide; stearic acid; sulfur; carbon black; antioxidants; and a vulcanization accelerator, wherein the dry rubber is obtained from a non-Hevea plant.
[0017] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF DRAWINGS
[0018] Having thus described the disclosure in general terms, references will now be made to the accompanying figures, wherein:
[0019] FIG. 1 illustrates a flowchart depicting a method for extracting and processing latex from a non-Hevea plant.
[0020] FIG. 2 illustrates a flowchart depicting a method for producing an elastomer.
[0021] It should be noted that the accompanying figures are intended to present illustrations of exemplary embodiments of the present disclosure. These figures are not intended to limit the scope of the present disclosure. It should also be noted that accompanying figures are not necessarily drawn to scale.
DETAILED DESCRIPTION
[0022] Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein reference numerals refer to like elements throughout the specification. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of embodiments of the present description. As used herein, the term ‘and/or’ includes any and all combinations of one or more of the associated listed items. Throughout the present disclosure, the expression ‘at least one of a, b and c’ indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.
[0023] The subject matter of the present application may include various modifications and various embodiments, and example embodiments will be illustrated in the drawings and described in more detail in the detailed description. Effects and features of the subject matter of the present disclosure, and implementation methods therefore will become clear with reference to the embodiments described herein below together with the drawings. The subject matter of the present application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
[0024] Hereinafter, embodiments of the present application will be described in more detail with reference to the accompanying drawings. The same or corresponding elements will be denoted by the same reference numerals, and thus, redundant description thereof will not be repeated.
[0025] It will be understood that although the terms ‘first,’ second,’ etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.
[0026] An expression used in the singular may also encompass the expression of the plural unless it has a clearly different meaning in the context.
[0027] In the following embodiments, it is to be understood that terms such as ‘including,’ ‘includes’, ‘having’, ‘comprises,’ and ‘comprising,’ are intended to indicate the existence of the features or elements disclosed in the specification and are not intended to preclude the possibility that one or more other features or elements may exist or may be added. Further, it is to be understood that the terms “component”, “components”, “agent”, and “agents” pertain to any of the features of the instant disclosure disclosed herein.
[0028] In order to facilitate an understanding of the composition and/or formulation and/or product discussed herein, a number of terms are defined below. The terms defined below, as well as other terms used herein, should be construed to include the provided definitions, the ordinary and customary meaning of the terms, and any other implied meaning for the respective terms. Thus, the definitions below do not limit the meaning of these terms but only provide exemplary definitions.
[0029] The present disclosure pertains to the field of natural rubber production and processing, and more specifically, to a method for extracting and processing latex from non-Hevea plant, particularly Cryptostegia grandiflora, and product thereof.
[0030] An aspect of the instant disclosure relates to a method for extracting and processing latex.
For the purpose of instant disclosure and as is perceivable to a person skilled in the art, the term “latex” pertains to a dispersion or emulsion of a polymer in water. A latex compound is a mixture of a latex polymer or blend of polymers with other chemical ingredients extracted from at least one plant source or mushroom, including but not limited to Hevea brasiliensis, Hevea guianensis, Landolphia owariensis, Manilkara zapota, Castilla elastica, Parthenium argentatum, Euphorb family (Euphorbiaceae), milkweed family (Asclepiadaceae), mulberry family (Moraceae), dogbane family (Apocynaceae), and chicory tribe (Lactuceae) of the sunflower family (Asteraceae), Lactarius deliciosus (saffron milk cap), Lactarius indigo (indigo milk cap), Lactarius torminosus (woolly milk cap), Lactifluus piperatus (peppery milk cap), as is perceivable to a skilled person in the art.

An embodiment of the instant disclosure relates to a method for extracting and processing latex from a non-Hevea plant (referring to plant species that do not belong to the Hevea genus), including but not limited to, Taraxacum kok-saghyz, Ficus elastica, Parthenium argentatum, Lactuca sativa, Papaver somniferum, Euphorbia tirucalli, Asclepias syriaca, Jatropha curcas, Ficus carica, Calotropis procera, Euphorbia pulcherrima, Cryptostegia grandiflora, Plumeria rubra, Cynanchum viminale, and Manihot esculenta; and preferably, from Cryptostegia grandiflora.

In an embodiment, the method comprises collecting latex; preferably from the non-Hevea plant discussed above.
In a related embodiment, the latex is collected via at least one of tapping, scoring/slashing, scraping, exudation from cuts, milking by pressure, and vacuum extraction perceivable to a person skilled in the art; and preferably, via tapping as is conventionally known.
In another related embodiment, the collected latex is optionally concentrated; preferably, via centrifugation, as is perceivable to a skilled person in the art.
In yet another related embodiment, the (collected) latex is stable in presence of metallic salt, EDTA, and at temperatures below −30°C.
As will be understood by a person skilled in the art, this may play a critical role in facilitating storage and transportation
[0031] In an embodiment, the method comprises carrying out coagulation.
For the purpose of instant disclosure and as is perceivable to a person skilled in the art, the term “coagulation” / “coagulated” pertains to the process where liquid latex solidifies into rubber by the action of acids or naturally over time. The latex particles aggregate and separate from the liquid, forming a solid mass called coagulated rubber mass.
In a related embodiment, the coagulation is carried out chemically or mechanically; preferably to obtain the coagulated rubber mass.
In another related embodiment, the chemical coagulation is carried out using a coagulating agent.
In a related embodiment, the coagulating agent is selected from solvent having general formula as: CnH2n+1OH (where n ≥ 1), CnH2n+1COOH (where n ≥ 1), or CnH2nO (where n ≥ 3), including but not limited to acetic acid, ethyl alcohol, ethyl methyl alcohol, formic acid, citric acid, ketone, and homologous series thereof.
In another related embodiment, quantity of the coagulating agent ranges from 10g to 500g.
In yet another embodiment, ratio of the coagulating agent to the latex ranges from 10-100 g: 10-200 g.
In another embodiment, the method comprises adding at least one coagulating agent; preferably to obtain a coagulated rubber mass in a controlled manner under continuous stirring.
In a related embodiment, stirring is carried out for 20 mins to 40 mins.
In another related embodiment, the mechanical coagulation is carried out via stirring/centrifugation.
In a related embodiment, stirring is carried out using conventionally known stirring methods, including agitation, preferably at about 1000 RPM to 15000 RPM.
In another related embodiment, the centrifugation is carried out at about 5000 RPM to 15000 RPM.
[0032] In an embodiment, the method comprises separating the coagulated rubber mass from liquid phase.
For the purpose of instant disclosure and as is perceivable to a person skilled in the art, the term “liquid phase” pertains to watery, non-rubber portion remaining after latex coagulates. It contains water, proteins, sugars, and other soluble substances separated from the solid rubber mass during processing.
In a related embodiment, the separation is carried out via decantation, centrifugation, filtration, pressing/squeezing, settling/sedimentation, vacuum drainage, and/or mechanical pressing (e.g., roller presses) methods, as is perceivable to a person skilled in the art.
In a preferable embodiment, the separation is carried out by decantation, followed by squeezing or centrifugation.
In a related embodiment, the pH of the liquid phase ranges from 1 to 3.
[0033] In another embodiment, the method comprises washing the coagulated rubber mass with water; and preferably with distilled water.
Washing aids in the removal of residual chemicals and impurities.
[0034] In yet another embodiment, the method comprises drying the coagulated rubber mass to obtain dry rubber.
In a related embodiment, drying is carried out via air drying (natural drying), smoke drying, hot air drying, vacuum drying, oven drying, freeze drying, or infrared drying; preferably at a temperature ranging from 70°C to 80°C; particularly, for 20-30 h.
[0035] In a further embodiment, one or more features or steps described in any of the previous embodiments are repeated, combined, or applied again to enhance or modify the invention.
[0036] Referring to Fig. 1, an exemplary embodiment of the instant disclosure relates to a method for extracting and processing latex from a plant, the method comprising, collecting latex from the plant via tapping; carrying out coagulation, wherein the coagulation is carried out chemically or mechanically to obtain a coagulated rubber mass; separating the coagulated rubber mass from liquid phase; washing the coagulated rubber mass with water; and drying the coagulated rubber mass to obtain dry rubber, wherein the plant is a non-Hevea plant, as described above.
[0037] In an embodiment, % of the dry rubber (DRC) obtained ranges from 28% to 45%.
In another embodiment, Poly dispersibility index (PDI) of the dry rubber is ≤ 2.95.

[0038] In an embodiment, the dry rubber is extracted using acetone, preferably to determine percentage of extractable content.
This extraction may be performed under standard laboratory conditions, for example, by immersing the rubber sample in acetone for a defined period and temperature, thereby allowing soluble components such as resins, oils, and other non-rubber materials to dissolve. The extractable content can then be quantified, for instance, by evaporating the acetone and weighing the remaining residue, which provides a measure of the non-rubber constituents present in the sample.
In a related embodiment, the extraction is carried out using Soxhlet extraction, as is perceivable to a person skilled in the art.
In an embodiment, the percentage of extractable% of the dry rubber obtained ranges from 4% to 7%.
[0039] Another aspect of the instant disclosure relates to a method for producing an elastomer.
For the purpose of instant disclosure and as is perceivable to a person skilled in the art, the term “elastomer” pertains to a mixture comprising raw or synthetic rubber and one or more additional components such as fillers, plasticizers, vulcanizing agents, accelerators, antioxidants, processing aids, and other additives, formulated to achieve specific physical, chemical, or mechanical properties after vulcanization.
[0040] In an embodiment, the method comprises compounding and mixing the dry rubber described above with one or more additional components such as fillers, plasticizers, processing oils, vulcanizing agents, accelerators, antioxidants, processing aids, and other additives, including but not limited to carbon black, silica, clay, calcium carbonate, zinc oxide, stearic acid, Paraffinic oil, TDQ, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), Naphthenic oil, aromatic oils, phenylene diamine, dihydroquinoline derivates, esters, sulfur, peroxides, Mercaptobenzothiazole disulfide (MBTS), N-Cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazolesulfenamide (TBBS) or its derivatives, Thiazoles, Sulfenamides. Dithiocarbamates, Thiurams, Guanidine derivatives, colorants, tackifiers, thickeners, defoamers, preservatives, surfactants, thickeners, flame retardants, and like.
In an embodiment, the vulcanization accelerator is selected from N-tert-butyl-2-benzothiazolesulfenamide (TBBS) or its derivatives, and the antioxidants are TDQ and 6PPD.
For the purpose of instant disclosure and as is perceivable to a person skilled in the art, the term “compounding” or “compounded” pertains to process of mixing raw latex with various additives and chemicals to produce a formulated latex compound with the desired properties for a specific application.
In a related embodiment, one or more tanks, chambers, or/and associated milling equipment may be employed as appropriate, with design and configuration selected based on the compounding conditions and formulation parameters.
In a preferred embodiment, compounding and mixing are carried out via milling; and preferably, using a two-roll mill (open mixing) or an internal closed chamber mixing (closed mixing chamber with oppositely rotating rotors), and the vulcanization is carried out at a temperature ranging from 140°C to 180°C.
In another embodiment, the order of addition and the timing of incorporation of the aforementioned components during compounding and/or mixing may be selectively controlled, optionally based on the specific formulation requirements or desired properties of final product (elastomer).
In yet another embodiment, concentration of the zinc oxide, the stearic acid, the carbon black, the sulphur, antioxidants, and the vulcanization accelerator is 3-6, 1-3, 30-80, 1.25-3.25, 1-5, and 0.60-0.80 parts per 100 of the dry rubber, respectively
[0041] In another embodiment, the method comprises molding and vulcanizing the compounded rubber to obtain the elastomer.
[0042] In a related embodiment, molding is performed using a hydraulically operated machine equipped with precise control systems for temperature, time, and pressure. A metal mold is employed to impart the desired shape to the elastomer following vulcanization within the molding process. The molding parameters may be set in accordance with TC 90 specifications.
[0043] Referring to Fig. 2, an exemplary embodiment of the instant disclosure relates to a method for producing an elastomer, the method comprising, compounding and mixing the dry rubber as claimed in claim 1 with zinc oxide, stearic acid, sulfur, carbon black, antioxidants, and a vulcanization accelerator via milling to obtain a compounded rubber; and molding and vulcanizing the compounded rubber to obtain the elastomer, as described above.
[0044] A further aspect of the instant disclosure relates to an elastomer comprising a dry rubber; zinc oxide; stearic acid; sulfur; carbon black; antioxidants; and a vulcanization accelerator, wherein the dry rubber is obtained from a non-Hevea plant, as described above.
In an embodiment, the non-Hevea plant is Cryptostegia grandiflora, as described above.
In another embodiment, the vulcanization accelerator is selected from N-tert-butyl-2-benzothiazolesulfenamide (TBBS) or its derivatives, and the antioxidants are TDQ and 6PPD, as described above.
In yet another embodiment, concentration of the zinc oxide, the stearic acid, the carbon black, the sulphur, and the vulcanization accelerator is 3-6, 1-3, 30-80, 1.25-3.25, 1-5, and 0.60-0.80 parts per 100 of the dry rubber, respectively, as described above.
In a further embodiment, Poly dispersibility index (PDI) of the dry rubber is ≤ 2.95, as described above.
[0045] Various modifications to the embodiment will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated but is to be accorded with the widest scope consistent with the principles and features described herein.
[0046] The foregoing description shall be interpreted as illustrative and not in any limiting sense. A person of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. The features and properties of the present disclosure are described in further detail below with reference to examples.
[0047] Example 1: Method for extracting and processing latex from a non-Hevea Plant
For this experiment, latex was collected from a non-Hevea plant, Cryptostegia grandiflora via conventional tapping and subjected to processing and characterization as described below.
The collected latex may be optionally concentrated; preferably, via centrifugation, as is perceivable to a skilled person in the art.
Table 1 represents the characterization of Hevea brasiliensis latex (commercially sourced) and the latex collected from a non-Hevea plant, Cryptostegia grandiflora.
[Table 1]
Properties Method Observed Value
Hevea brasiliensis Cryptostegia grandiflora
Brookfield Viscosity Spindle no. 2 /RT/100 RPM ASTM 1076

28 CPS 45-51 CPS
Protein Analysis

ASTM 1076 and ASTM D5712
1.6% 0.3%
Dry rubber Content
( DRC )

ASTM D 1076

37.3% 30.6%
Total Solid content
(TSC)
ASTM D 1076

37.9% 36%-39%
Cupper
( By ICP* )
ISO 19050

Not Detected
Not Detected

Protein content ASTM 1076 & ASTM D5712 Approx. 1.6 Approx. 0.3
Manganese
( By ICP* )
ISO 19050

Not Detected
Not Detected

**Detection limit is 5ppm
Part 1: Coagulation carried out chemically:
Example 1A: processing of the latex using coagulating agents having the general formula CnH2n+1COOH (where n ≥ 1)
For this experiment, about 50 g of a freshly tapped latex, having a total solid content (TSC) of about 36%-39% and an initial pH of about 4-5, was placed in a container. Acetic acid (about 50 g) or its homologous series was added gradually under constant stirring conditions for about 30 minutes to initiate coagulation and form a coagulated rubber mass.
Upon completion, the coagulated rubber mass was separated from the liquid phase (having a pH = 1 to 2) by decantation, followed by squeezing. The coagulated rubber mass was washed thoroughly with distilled water to remove residual acid, then dried in an air-circulated oven at about 70–80 °C for about 20-30 h. in sheet form to obtain dry rubber. The resulting % of the dry rubber (DRC) was observed to be about 30%. The dried rubber was subjected to conventional Soxhlet extraction using acetone (purity: 99%), yielding an extractable (%) content of about 7%.
Comparative analysis
As a comparison, an identical procedure was followed for the commercially sourced Hevea brasiliensis latex (50 g, TSC 37.5%, pH 9.95). For this, about 15 g of acetic acid was added as a coagulating agent. The DRC obtained was 36.8%, and the acetone extractable (%) content was 4.5%.
GPC Analysis (conventionally practised) was performed. The results are illustrated in Table 2.
[Table 2]
Hevea brasiliensis (dry rubber) Cryptostegia grandiflora (dry rubber)
Mn Mw Polydispersibility index (PDI) Mn Mw Polydispersibility index (PDI)
265,313 797,380 3.0 729,265 2,144,962 2.94
The results showed a higher molecular weight and lower PDI for Cryptostegia grandiflora (dry rubber), indicating a more uniform molecular weight distribution and the potential for enhanced or comparable mechanical properties such as strength and toughness.
Method for producing an elastomer
The dry rubber obtained above was compounded and mixed according to the standard formulation provided in Table 3 to obtain a compounded rubber. The compounding was carried out using a laboratory two-roll mill (size: 6 × 13 inch) or an internal closed chamber mixing under controlled conditions to ensure uniform mixing of all ingredients.
[Table 3]
Ingredient Parts per 100 Rubber
Dry Rubber 100
Zinc Oxide 3-6
Stearic Acid 1-3
Carbon Black (N550) 30-80 (depending on the hardness requirement)
Sulphur 1.25-3.25
Vulcanization Accelerator (N-tert-butyl-2-benzothiazolesulfenamide (TBBS)) 0.60-0.80
TDQ 3
6PPD 3
Total 150.95

The prepared compound was then moulded using a hydraulically operated machine equipped with precise control systems for temperature, time, and pressure in accordance with TC 90 specifications to form test sheets with a uniform thickness of approximately 2 mm. The molding was followed by curing at a temperature of about 140°C to 180°C for about 5 - 15 minutes to obtain vulcanized rubber sheets/elastomer suitable for physical and rheological property evaluation.
For comparative rheological characteristics and physical properties (summarized in Table 4), the experiment was repeated for Hevea brasiliensis.
[Table 4]
Properties Cryptostegia grandiflora (elastomer) Hevea brasiliensis (elastomer)
Rheological Properties (150 ◦C for 30 minutes)
ML 0.40 0.29
MH 11.49 11.46
TS2 3.54 2.97
TC90 8.66 6.37
Tensile Strength (MPa) 20.5 23
Elongation (%) 509 447
100% (MPa) 2.1 2.3
200% (MPa) 4.8 6.4
300% (MPa) 8.8 12.6

Interpretation: As seen in Table 4, Cryptostegia grandiflora (elastomer) derived from coagulating agents having the general formula CnH2n+1COOH (where n ≥ 1) demonstrated comparable mechanical properties with Hevea brasiliensis (elastomer), demonstrating its suitability as an alternative to Hevea brasiliensis (elastomer).

The Mooney viscosities of the dry rubbers derived from Cryptostegia grandiflora and Hevea brasiliensis were also measured to assess their processability and viscoelastic behavior. The test was carried out in accordance with ASTM D1646, using a Mooney viscometer at about 100 °C with a large rotor and a test duration of about 4 minutes following about 1 minute of preheating, i.e., ML (1+4) at about 100 °C.
The results are summarized in Table 5.
[Table 5]

Mooney Viscosity ML (1+4) @100 ◦ C

Hevea brasiliensis (elastomer) 81.2
Cryptostegia grandiflora (elastomer) 79.6

Interpretation: The data indicates that the Mooney viscosity of Cryptostegia grandiflora (elastomer) is closely comparable to that of Hevea brasiliensis (elastomer), confirming its suitability for conventional rubber processing techniques. This, in conjunction with its comparable physical properties and lower polydispersity index (PDI), provides strong supporting evidence that the elastomer obtained from Cryptostegia grandiflora latex is a viable substitute for Hevea natural rubber in various elastomeric applications.
Example 1B: processing of the latex using coagulating agents having the general formula CnH2nO (where n ≥ 3)
This experiment was conducted using acetone as a representative polar organic solvent (ketone group). About 125 g a freshly tapped latex obtained above (TSC of about 36%-39% and an initial pH of about 4-5) was treated with acetone added slowly under mild stirring as described above. The mixture was stirred continuously for 30 minutes as described above. A maximum of 50 g acetone was sufficient to coagulate the latex, forming a coagulated rubber mass and a separate liquid phase.
The coagulated rubber was separated by squeezing to remove the liquid, cut into small pieces, and washed again with acetone to remove trapped solvent. The mass was dried at about 70–80 °C for about 20-30 h. in sheet form to obtain dry rubber. The DRC was found to be 34%, with 4% acetone extractables (Soxhlet extraction).
Comparative analysis
A similar procedure was followed for the commercially sourced Hevea brasiliensis latex (50 g, TSC 37.5%, pH 9.95). A total of 130 g acetone was required for coagulation. The DRC obtained was 36%, and acetone extractables were 2%.
GPC Analysis (conventionally practised) was performed. The results are illustrated in Table 6.
[Table 6]
Hevea brasiliensis (dry rubber) Cryptostegia grandiflora (dry rubber)
Mn Mw Polydispersibility index (PDI) Mn Mw Polydispersibility index (PDI)
244,854 828,226 3.38 851,995 2,310,399 2.71
Interpretation: It was noted that Crypto latex required approximately 64% less acetone than Hevea latex to achieve complete coagulation. The higher molecular weight and lower PDI of Crypto rubber suggest potential for enhanced or comparable mechanical properties such as strength and toughness. The dry rubber obtained in this experiment was implemented for producing an elastomer as described in Example 1A and compared with Hevea brasiliensis (elastomer) (summarized in Table 7)
[Table 7]
Properties Cryptostegia grandiflora (elastomer) Hevea brasiliensis (elastomer)
Rheological Properties (150 ◦C for 30 minutes)
ML 0.42 0.29
MH 13.95 11.46
TS2 4.50 2.97
TC90 9.73 6.37
Tensile Strength (MPa) 22.2 23
Elongation (%) 415 447
100% (MPa) 5 2.3
200% (MPa) 10 6.4
300% (MPa) 15 12.6
Interpretation: As seen in Table 7, Cryptostegia grandiflora (elastomer) derived from coagulating agents having the general formula CnH2nO (where n ≥ 3) demonstrated comparable mechanical properties with Hevea brasiliensis (elastomer), demonstrating its suitability as an alternative to Hevea brasiliensis (elastomer).
Studying the optimum latex-to-coagulating agent ratio
For this experiment, Methyl Ethyl Ketone (MEK) was used as the coagulating agent, and the processing of the latex (obtained previously) was performed as discussed in Examples 1A/1B. However, to calculate the optimum latex-to-coagulating agent ratio, in separate trials, about 50 g of MEK was used in different containers, and varying amounts of the latex (previously obtained) were added to calculate DRC (Table 8).
[Table 8] Comparative analysis for optimum latex-to-coagulating agent ratio
Quantity of Latex DRC%
128 41.2
83.3 44.2
62.5 39.2

Observation: Immediate coagulation was observed upon MEK addition. The coagulated rubber mass was washed and dried using the procedure discussed in Example 1A/1B. It was observed that the 83.3 g latex sample resulted in the highest DRC, suggesting it was the optimal latex-to-coagulating agent ratio for MEK-based coagulation.
Example 1C: processing of the latex using coagulating agents having the general formula CnH2n+1OH (where n ≥ 1) and studying optimum latex-to-coagulating agent ratio
This experiment evaluated ethyl alcohol as a coagulating agent. In separate trials, 50 g of ethyl alcohol was placed in a container, and different amounts of Cryptostegia latex were added (Table 9).
[Table 9] Comparative analysis for optimum latex-to-coagulating agent ratio
Quantity of Latex DRC%
128 35.2
83.3 36
62.5 34.5
It was observed that 83.3 g latex gave the maximum DRC. Further trials confirmed that 62.5 g latex could be completely coagulated by about 50 g ethyl alcohol with no uncoagulated latex remaining. A comparative experiment was conducted with the commercially sourced Hevea latex, using the same latex quantities (128 g, 83.3 g, and 62.5 g). In each case, 190 g of ethyl alcohol was required to achieve complete coagulation.
Corresponding DRCs for Hevea latex (Table 10)
[Table 10] Comparative analysis for optimum latex-to-coagulating agent ratio
Quantity of Latex DRC%
128 36
83.3 36
62.5 37

Interpretation: These results demonstrated that Cryptostegia latex required approximately 3.8 times less ethyl alcohol than Hevea latex to achieve coagulation, while yielding comparable DRC values.
Part 2: Coagulation carried out mechanically:
As an alternative to the chemical coagulation method described above, mechanical coagulation was performed using either stirring (via agitation) or centrifugation to obtain the coagulated rubber mass.
During stirring via agitation, an agitator of capacity was maximum of about 7000 RPM, with a timer facility was implemented. The agitation was initially commenced at about 1000 RPM (with a run for 15 minutes), and the coagulated rubber mass was collected. The collected Crypto latex (as previously described) was again stirred for about 15 minutes at about 1000 RPM. Thus, with every 15 minutes, the coagulated rubber mass was collected for about 1 hour of agitation. Alternatively, for centrifugation, the collected Crypto latex (as previously described) was subjected to about 12000 RPM for about 20 minutes, and the coagulated rubber mass obtained therefrom was collected. Again, the Crypto latex was subjected to centrifugation for 10 minutes, and the coagulated rubber mass obtained therefrom was collected. This procedure was repeated at 12000 RPM for another 5 minutes to achieve the coagulated rubber mass.
After obtaining the coagulated rubber mass, subsequent experiments were conducted in accordance with the procedures described in the preceding examples.
Example 2: Stability Testing
Example 2A: Chemical Stability of Crypto Latex in Presence of Metallic Salts and Chelating Agents
The stability of the latex obtained from Cryptostegia grandiflora (as discussed above) was assessed under the following chemical conditions:
In Test 1, about 10 g of the Crypto latex was treated with about 10 g of about 5% aqueous solution of aluminum sulfate [Al₂(SO₄)₃]. In Test 2, about 10 grams of the Crypto latex was mixed with about 10 grams of a 40% aqueous solution of alum (aluminum potassium sulfate). In Test 3, about 10 g of Crypto latex was mixed with about 10 g of 40% alum solution and about 10 g of 5% Al₂(SO₄)₃. In Test 4, about 10 grams of Crypto latex was treated with 10 grams of a 5% aqueous solution of ethylene diamine tetraacetic acid (EDTA).
Results: No coagulation observed in Tests 1-4
Comparative Analysis: For this, commercially sourced Hevea latex was subjected to the same conditions. It was found that Hevea latex coagulated immediately upon treatment with the 5% Al₂(SO₄)₃ solution. Specifically, 10 grams of Hevea latex with an equivalent total solid content (TSC) coagulated completely when mixed with 14 grams of the 5% aluminum sulfate solution. Complete coagulation was also observed when 10 grams of Hevea latex was treated with 10 grams of a 40% aluminum sulfate solution. Moreover, partial coagulation was observed when 10 grams of Hevea latex was treated with a 5% EDTA solution.
Interpretation: this indicates that latex obtained from Cryptostegia grandiflora exhibited significantly higher chemical stability in the presence of metallic salts and EDTA compared to Hevea latex; thereby highlighting its enhanced transportation and storage capabilities.

Example 2B: Thermal Stability of Crypto Latex at Low Temperatures
To evaluate the thermal stability of Cryptostegia grandiflora latex (obtained previously), about 50 g of the Crypto latex was diluted with about 100 g of distilled water and subsequently exposed to low temperatures. The diluted mixture was placed at –30°C for 30 minutes.
Result: Although the entire mass froze, no coagulation was observed, and upon returning to ambient temperature, the latex recovered its original emulsion state.
A similar result was obtained when the Crypto latex mixture was kept at –60°C for 30 minutes—the emulsion froze but did not coagulate, and the original emulsion characteristics were restored upon thawing.
Identical testing conducted on the commercially sourced Hevea latex revealed similar thermal behavior, with no coagulation at –30°C and –60°C for 30 minutes. Interpretation: The Cryptostegia grandiflora latex demonstrated comparable low-temperature stability to that of Hevea latex.

The instant disclosure achieves the following advantages:
- Versatility in Coagulation: Crypto latex can be coagulated using both chemical and mechanical methods. Mechanical coagulation may be achieved through stirring or centrifugation. In the case of chemical coagulation, a wide range of coagulating agents—including acids, ketones, and alcohols—can be employed, offering enhanced flexibility in processing techniques.
- Reduced Coagulating Agent Requirement: The quantity of coagulating agents required—particularly in the case of ketones and alcohols—is substantially lower compared to traditional natural latexes (like Hevea), resulting in cost savings and improved environmental compliance.
- Chemical and Thermal Stability: The Crypto latex exhibits high stability in the presence of metallic salts and chelating agents (such as EDTA), and remains stable even under sub-zero temperatures (e.g., –30°C and –60°C), thereby enhancing its suitability for diverse storage and handling conditions.
- The Crypto elastomer demonstrates comparable mechanical properties and Polymer Characteristics with Hevea elastomer – thereby emphasizing its potential as an alternative to Hevea.
[0048] The methods described herein may be implemented in a fully automated, semi-automated, or manual manner, depending on the scale of production and operational requirements. The process is adaptable for large-scale industrial manufacturing as well as medium- and small-scale production setups.
[0049] The subject disclosure is applicable across various sectors of the rubber industry, including but not limited to the manufacture of tires, automotive components, industrial goods (such as conveyor belts and hoses), footwear, medical devices (such as gloves and catheters), latex-based products, consumer products, and specialty elastomer applications.
[0050] While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present application as defined by the following claims, and equivalents thereof.
, Claims:WE CLAIM:
1. A method for extracting and processing latex from a plant,
the method comprising:
collecting latex from the plant via tapping;
carrying out coagulation,
wherein the coagulation is carried out chemically or mechanically to obtain a coagulated rubber mass;
separating the coagulated rubber mass from liquid phase;
washing the coagulated rubber mass with water;
and drying the coagulated rubber mass to obtain dry rubber,
wherein the plant is a non-Hevea plant.

2. The method as claimed in claim 1, wherein the chemical coagulation is carried out using a coagulating agent, and wherein the mechanical coagulation is carried out via stirring/centrifugation.

3. The method as claimed in claim 1, wherein the non-Hevea plant is Cryptostegia grandiflora.

4. The method as claimed in claim 1, wherein the latex is stable in presence of metallic salt, EDTA, and at temperatures below −30°C.

5. The method as claimed in claim 2, wherein the coagulating agent is selected from solvent having general formula as: CnH2n+1OH (where n ≥ 1), CnH2n+1COOH (where n ≥ 1), or CnH2nO (where n ≥ 3).

6. The method as claimed in claim 1, wherein the separation is carried out by decantation, followed by squeezing or centrifugation, and the drying is carried out at a temperature ranging from 70°C to 80°C for 20-30 h.

7. The method as claimed in claim 1, wherein % of the dry rubber obtained ranges from 28% to 45%.

8. The method as claimed in claim 1, wherein extractable% of the dry rubber obtained ranges from 4% to 7%.

9. A method for producing an elastomer,
the method comprising:
compounding and mixing the dry rubber as claimed in claim 1 with zinc oxide, stearic acid, sulfur, carbon black, antioxidants, and a vulcanization accelerator via milling to obtain a compounded rubber; and
molding and vulcanizing the compounded rubber to obtain the elastomer.

10. The method as claimed in claim 9, wherein the vulcanization accelerator is selected from N-tert-butyl-2-benzothiazolesulfenamide (TBBS) or its derivatives, and the antioxidants are TDQ and 6PPD.

11. The method as claimed in claim 9, wherein concentration of the zinc oxide, the stearic acid, the carbon black, the sulphur, the antioxidants, and the vulcanization accelerator is 3-6, 1-3, 30-80, 1.25-3.25, 1-5, and 0.60-0.80 parts per 100 of the dry rubber, respectively.

12. The method as claimed in claim 9, wherein the milling is carried out using a two-roll mill or an internal closed chamber mixing, and the vulcanization is carried out at a temperature ranging from 140°C to 180°C.
.
13. An elastomer comprises:
a dry rubber;
zinc oxide;
stearic acid;
sulfur;
carbon black;
antioxidants; and
a vulcanization accelerator,
wherein the dry rubber is obtained from a non-Hevea plant.

14. The elastomer as claimed in claim 13, wherein the non-Hevea plant is Cryptostegia grandiflora.

15. The elastomer as claimed in claim 13, wherein the vulcanization accelerator is selected from N-tert-butyl-2-benzothiazolesulfenamide (TBBS) or its derivatives, and the antioxidants are TDQ and 6PPD.

16. The elastomer as claimed in claim 13, wherein concentration of the zinc oxide, the stearic acid, the carbon black, the sulphur, the antioxidants, and the vulcanization accelerator is 3-6, 1-3, 30-80, 1.25-3.25, 1-5, and 0.60-0.80 parts per 100 of the dry rubber, respectively.

17. The elastomer as claimed in claim 13, wherein Poly dispersibility index (PDI) of the dry rubber is ≤ 2.95.