Claims:We Claim:

1. A biodegradable polymer composition, the composition comprising:
- 30-60 % w/w of polybutylene adipate terephthalate (PBAT),
- about 40 % w/w or higher of a modified starch,
wherein thermogravimetric analysis of the biodegradable polymer composition shows a characteristic peak at a degradation temperature ranging between 320-340°C.

2. The biodegradable polymer composition as claimed in claim 1, comprising 40-60% w/w of the PBAT.

3. The biodegradable polymer composition as claimed in claim 1, wherein the biodegradable polymer composition has a notched izod impact strength of at least 20 KJ/m2, measured in accordance with ASTM D256.

4. The biodegradable polymer composition as claimed in claim 1, wherein the biodegradable polymer composition has a melt flow index in a range of 3-11 g/10 minutes, measured in accordance with ASTM D1238.

5. The biodegradable polymer composition as claimed in claim 1, wherein PBAT has a molecular weight in the range of 9 X 104 -15 X 104 Da.

6. The biodegradable polymer composition as claimed in claim 1, wherein the modified starch comprises starch and a compatibilizing agent in a w/w ratio of 2:1- 4:1.

7. The biodegradable polymer composition as claimed in claim 6, wherein the modified starch comprises starch and the compatibilizing agent in the w/w ratio of 3.34:1.

8. The biodegradable polymer composition as claimed in claim 1, wherein the modified starch has a solubility index of less than 15 % in water at a temperature of about 80°C.

9. The biodegradable polymer composition as claimed in claim 1, wherein the biodegradable polymer composition is in the form of a film or pellets.

10. The biodegradable polymer composition as claimed in claim 1, further comprising one or more fillers.

11. A biodegradable polymer composition, the composition comprising:
- 30- 60% w/w of polybutylene adipate terephthalate (PBAT),
- at least 40 % w/w of a modified starch,
wherein the biodegradable polymer composition has an impact strength of at least 30 KJ/m2, measured in accordance with ASTM D256.

12. The biodegradable polymer composition as claimed in claim 11, wherein the biodegradable polymer composition has a melt flow index in a range of 3-11 g/10 minutes, measured in accordance with ASTM D1238.

13. A biodegradable polymer composition, the composition comprising:
- 30- 50% w/w of polybutylene adipate terephthalate (PBAT),
- at least 50 % w/w of a modified starch,
wherein the biodegradable polymer composition has an impact strength of at least 30 KJ/m2, measured in accordance with ASTM D256 and a melt flow index in a range of 3-11 g/10 minutes, measured in accordance with ASTM D1238.

14. A packaging material comprising a biodegradable polymer composition, said biodegradable polymer composition comprising:
- 30-60 % w/w of polybutylene adipate terephthalate,
- at least 40 % w/w of a modified starch,
wherein thermogravimetric analysis of the biodegradable polymer composition shows a characteristic peak at a degradation temperature ranging between 320-340°C.

15. A film having a thickness of 30-120 microns formed from a biodegradable polymer composition, said biodegradable polymer composition comprising:
- 30-60 % w/w of polybutylene adipate terephthalate,
- at least 40 % w/w of a modified starch,
wherein thermogravimetric analysis of the biodegradable polymer composition shows a characteristic peak at a degradation temperature ranging between 320-340°C.

Dated this 13th day of January 2022

Essenese Obhan
Of Obhan & Associates
Agent for the Applicant
Patent Agent No. 864
 
, Description:Field of Invention

The present disclosure relates to a biodegradable polymer composition. Specifically, the present disclosure relates to a biodegradable polymer composition comprising a modified starch and polybutylene adipate co-terephthalate.

Background

Biodegradable materials and environmentally friendly alternatives for plastic are increasingly being adopted in various industries, including for example packaging. Starch is easily available, renewable, biodegradable and generally low cost and has been used for preparing biodegradable plastics. However, starch films are brittle and starch, a hydrophilic material, tends to deteriorate on exposure to humidity. These factors make starch unsuitable for preparing biodegradable plastics especially for food packaging.

To overcome such limitations, starch is modified and blended with other polymers. Modification of starch includes for example plasticization and gelatinization that weaken the inter-molecular hydrogen bonding of the starch molecule. Polymers typically used for blending with starch are polyvinyl alcohol (PVA), polylactic acid (PLA), polycaprolactone (PCL), polybutylene adipate co-terephthalate (PBAT). While PBAT is a completely biodegradable aliphatic-aromatic copolyester with competitive mechanical properties in comparison to low-density polyethylene (LDPE), it is very expensive.

WO 2009/073197 discloses a starch-polyester graft copolymer formed by the reactive blending of a thermoplastic starch with a biodegradable polyester. However, as disclosed by Garalde et al., The effects of blend ratio and storage time on thermoplastic starch/poly(butylene adipate-coterephthalate) films, Heliyon 5 (2019) e01251, such blends of starch and PBAT at 20, 40, and 60 wt% of starch suffer from disadvantages such as low miscibility. Starch-PBAT blends with high starch concentration are also known to result in deterioration of mechanical properties, especially impact strength.
Summary

The present disclosure relates to a biodegradable polymer composition. Specifically, the present disclosure relates to a biodegradable polymer composition comprising 30-60% w/w of polybutylene adipate co-terephthalate (PBAT), and at least 40% w/w of a modified starch, wherein the thermogravimetric analysis of the biodegradable polymer composition shows a characteristic peak at a degradation temperature ranging between 320-340°C.

Brief Description of Drawings

Figure 1 shows the Scanning Electron Microscopy (SEM) images of prior art thermoplastic starch /PBAT films (Garalde et al., 2019).

Figure 2 shows the SEM images of a biodegradable polymer composition, in accordance with an embodiment of the present disclosure.

Figure 3 shows thermogravimetric analysis of a biodegradable polymer composition, obtained in accordance with an embodiment of the present disclosure.

Figure 4 shows a comparative study of the solubility of the modified starch used to prepare the biodegradable polymer composition, in accordance with an embodiment of the present disclosure.

Detailed Description

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the disclosed composition and method, and such further applications of the principles of the disclosure therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
Reference throughout this specification to “one embodiment”, “an embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase “in one embodiment”, “in an embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms “a,” “an,”, and “the” are used to refer to “one or more” (i.e. to at least one) of the grammatical object of the article.
The present disclosure relates to a biodegradable polymer composition. Specifically, the present disclosure relates to a biodegradable polymer composition comprising 30-60 % w/w of PBAT, about 40 % w/w or higher of a modified starch, wherein the thermogravimetric analysis of the biodegradable polymer composition shows a characteristic peak at a degradation temperature ranging between 320-340°C.
Herein, “characteristic peak” refers to a peak obtained at a certain degradation temperature, and which has a maximum derivative weight loss (%) greater than 1%.
In accordance with an aspect, the biodegradable polymer composition comprises PBAT as a continuous phase and the modified starch as a dispersed phase with improved dispersion uniformity and homogeneity, such that SEM images of the biodegradable polymer composition show a homogenous phase. As illustrated in Figure 1, SEM images of prior art TPS/PBAT films (Garalde et al., 2019) show miscibility limitations between PBAT and starch, with micro-fractures. In contrast, referring to Figure 2, SEM images of the disclosed biodegradable polymer composition show a homogenous phase indicating better miscibility between modified starch and PBAT.

In accordance with an embodiment, the biodegradable polymer composition has a notched izod impact strength of at least 20 KJ/m2, measured in accordance with ASTM D256. In accordance with some embodiments, the biodegradable polymer composition has the notched izod impact strength of at least 30 KJ/m2.
In accordance with an embodiment, the biodegradable polymer composition has a melt flow index (MFI) in a range of 3-11 g/10 minutes, measured in accordance with ASTM D1238. In accordance with some embodiments, the biodegradable polymer composition has the MFI of 6-11 g/10 minutes.
In accordance with an embodiment, the biodegradable polymer composition has an elongation at break of at least 150%, measured in accordance with ASTM D638. In accordance with some embodiments, the biodegradable polymer composition has the elongation at break of at least 300%.
The biodegradable polymer composition comprises at least 40% w/w of the modified starch. In some embodiments, the biodegradable polymer composition comprises 40-60% w/w of the modified starch.
The biodegradable polymer composition comprises 30-60% w/w of PBAT. In some embodiments, the biodegradable polymer composition comprises 40-60% w/w of PBAT. In accordance with an embodiment, PBAT used in the biodegradable polymer composition has a molecular weight in a range of 9 X 104 -15 X 104 Da.
The modified starch disclosed herein comprises starch and a compatibilizing agent in a w/w ratio ranging between 2:1- 4:1. In some embodiments, the modified starch comprises starch and the compatibilizing agent in the w/w ratio ranging between 3:1- 3.5:1. In accordance with a specific embodiment, starch and the compatibilizing agent are in the w/w ratio ranging between 3.3:1 to 3.4:1 and in particular 3.34:1.
Any known starch may be used to prepare the modified starch of present disclosure. In accordance with an embodiment, starch is a naturally occurring starch selected from a group consisting of potato, wheat, corn, cassava, rice and peas. In accordance with an embodiment, starch is one or more of a chemically or physically modified starch selected from a group consisting of oxidised, carboxymethylated, hydroxyalkylated, enzymatically treated starch. In some embodiments, a blend of natural as well as chemically or physically modified starch is used.

The compatibilizing agent is selected from a group consisting of glycerol, glycerin, sorbitol and combinations thereof. In accordance with a specific embodiment, the compatibilizing agent is glycerol.

The modified starch of the present disclosure is substantially insoluble in water. Particularly, the modified starch has a solubility index of less than 15 % in water at a temperature of about 80oC. It is understood that this solubility behavior is observed due to the saturated inter-molecular hydrogen bonding between starch and the compatibilizing agent during thermo-mechanical mixing of starch and the compatibilizing agent in accordance with the teachings of the present disclosure.

In accordance with an embodiment, the disclosed modified starch is insoluble in cold water maintained at a temperature of 10°C. In accordance with an embodiment, the disclosed modified starch has the solubility index in a range of 1%- 5% in water, at room temperature. In accordance with an embodiment, the modified starch has the solubility index in a range of 17%- 35% in boiling water. In accordance with an embodiment, the modified starch has the solubility index in the range of 1%- 5% in chloroform. Figure 4 shows a comparative solubility study of the modified starch when the ratio of starch and compatibilizing agent (glycerol) is 3.34:1. The solubility study was performed in cold water, water at room temperature, water at temperatures of 80°C and 90°C, boiling water and in chloroform.

In accordance with an embodiment, the thermogravimetric analysis of the modified starch shows a characteristic peak at a temperature between 120oC-180oC. In an embodiment, the characteristic peak is obtained at the temperature of about 150oC.

In accordance with an embodiment, the modified starch has a moisture content in the range of 0.4- 0.9%. In some embodiments, the modified starch has the moisture content of 0.6-0.7 %.
In a further embodiment, the modified starch comprises additives such as fillers, emulsifiers, fragrance, essential oils, fatty acids. Any known fillers may be used. In accordance with an embodiment, the fillers are selected from a group consisting of calcium carbonate, calcium oxides, coco peat, and combinations thereof. Any known emulsifier may be used. In accordance with an embodiment, the emulsifier is selected from a group consisting of tween 20, glycerol monostearate, alcohol ester and combinations thereof.

In accordance with an embodiment, the modified starch is in the form of pellets.

In accordance with an embodiment, the biodegradable polymer composition further comprises a filler. Any known filler may be used. In accordance with an embodiment, the filler is selected from a group consisting of calcium carbonate, micronized talc, nano-clay, micro-cellulose, nano-cellulose and a combination thereof.
A process for preparing the biodegradable polymer composition is also disclosed. Said process comprises processing at least 40 % w/w of the modified starch and 30-60 % w/w of polybutylene adipate terephthalate (PBAT) through a twin-screw processor at a barrel temperature ranging between 60-110°C, to obtain the biodegradable polymer composition.
In accordance with an embodiment, the modified starch and PBAT is processed through the twin-screw processor at the barrel temperature ranging between 90-110°C.
In accordance with an embodiment, the modified starch and biodegradable polymer composition are prepared in the same twin-screw processor. In some embodiments, said process comprises feeding the blend comprising starch and the compatibilizing agent to a first inlet of the twin-screw processor; processing the blend through the twin-screw processor at the barrel temperature ranging between 60-110°C to obtain the modified starch; feeding PBAT through a second inlet of the twin-screw processor; processing the modified starch and PBAT through the twin-screw processor at the barrel temperature ranging between 60-110°C; and obtaining the biodegradable polymer composition from a discharge zone of the twin-screw processor.
In accordance with an embodiment, the modified starch is in the form of pellets and is extruded with PBAT in the twin-screw processor to obtain the biodegradable polymer composition.
In accordance with an embodiment, the modified starch and the biodegradable polymer composition are prepared in at least two separate twin-screw processors connected in series. In accordance with an exemplary embodiment, said two twin-screw processors are connected in series, wherein the modified starch obtained from the first twin-screw processor is fed to the second twin-screw processor for processing with PBAT to obtain the biodegradable polymer composition. In accordance with an embodiment, the modified starch obtained from the first twin-screw processor is in the form of pellets.
In accordance with an embodiment, the twin-screw processor is operated at a screw speed of 80-140 rpm. In some embodiments, the twin-screw processor is operated at a screw speed of 80-120 rpm. In accordance with an embodiment, the twin-screw processor has a length/ diameter (L/D) in a range of 60/40. In an embodiment, the blend comprising starch and the compatibilizing agent is fed to the twin-screw processor at a feeding rate of 30-100 Kg/ hr. In accordance with an embodiment, PBAT is fed to the twin-screw processor at a feeding rate of 30-100 Kg/ hr. In accordance with an embodiment, the process parameters are varied such that the residence time varies between 1-4 minutes.
In accordance with an embodiment, said modified starch is prepared by a process comprising preparing a blend comprising starch and the compatibilizing agent in a w/w ratio ranging between 2:1 to 4:1, processing the blend comprising starch and the compatibilizing agent in a twin-screw processor at a barrel temperature ranging between 60-110°C; obtaining modified starch from a discharge zone of the twin-screw processor. The aforesaid process conditions subject starch and the compatibilizing agent to vigorous mechanical and thermal interaction such that the modified starch, which is substantially insoluble in cold water, water at room temperature as well as chloroform, is obtained.

In accordance with an embodiment, the blend comprising starch and the compatibilizing agent is prepared at room temperature of about 25–35 °C. In accordance with an embodiment, the blend comprising starch and the compatibilizing agent is prepared without the addition of water. In accordance with an embodiment, the processing of the blend comprising starch and the compatibilizing agent in the twin-screw processor is carried out without the addition of water. In accordance with an embodiment, the blend comprising starch and the compatibilizing agent is prepared in any known mixer. In some embodiments, said blend is prepared in a ribbon mixer.

In accordance with an embodiment, the twin-screw processor for preparing both the modified starch as well as the biodegradable polymer composition is a co-rotating twin-screw processor. In accordance with an embodiment, the co-rotating twin-screw processor is a co-rotating twin-screw extruder. In accordance with an exemplary embodiment, the twin-screw extruder is Omega 40H or Omega 60H (Steer Engineering Pvt. Ltd.).

A biodegradable polymer composition comprising 30- 60% w/w of polybutylene adipate terephthalate (PBAT) and at least 40 % w/w of a modified starch is disclosed. Said biodegradable polymer composition has an impact strength of at least 30 KJ/m2, measured in accordance with ASTM D256. In accordance with an embodiment, the biodegradable polymer composition has a melt flow index in a range of 3-11 g/10 minutes, measured in accordance with ASTM D1238.

A biodegradable polymer composition comprising 30- 50% w/w of polybutylene adipate terephthalate (PBAT), and at least 50 % w/w of a modified starch is disclosed. Said biodegradable polymer composition has an impact strength of at least 30 KJ/m2, measured in accordance with ASTM D256.

A packaging material comprising the aforesaid biodegradable polymer composition is also disclosed. Said packaging material comprises 40-100% w/w of said biodegradable polymer composition. In accordance with an embodiment, said packaging material comprises an additional polymer selected from a group consisting of polybutylene terephthalate (PBT) polyvinyl alcohol (PVA), polylactic acid (PLA), polycaprolactone (PCL), polyglycolic acid (PGA) and polybutylene succinate (PBS). Said packaging material may be in the form of film, foamed plastic, or fiber.

A film comprising the aforesaid biodegradable polymer composition is also disclosed. The film has a thickness in the range of 30-120 microns. In accordance with an embodiment, the film has the thickness in the range of 40-60 microns. Said film may be prepared using any known method of casting a polymer into a film.
In order that this disclosure may be better understood, the following examples are set forth. These examples are for the purpose of illustration only and the exact compositions, methods of preparation and embodiments shown are not limiting of the disclosure.

Also described herein are method for characterizing the biodegradable polymer compositions in accordance with one or more embodiments of the present disclosure.

Examples:

Example 1: Process for preparation of the exemplary biodegradable polymer composition
The biodegradable polymer composition was prepared by first preparing a blend comprising starch and glycerol at room temperature in a ribbon mixer. The blend comprising starch and glycerol was fed and conveyed through a twin-screw extruder. PBAT was fed to the twin-screw extruder through a side feeder. The modified starch and PBAT was conveyed through the twin-screw extruder and the biodegradable polymer composition- BPC1 was obtained from the discharge zone of the twin-screw extruder.

The ingredients used to form the exemplary biodegradable polymer composition (BPC1) are listed in Table 1, below.

Ingredient Quantity (%)
Starch 38.5
Glycerol 11.5
PBAT 50

Table 1: Ingredients for preparing exemplary biodegradable polymer composition

The machine specifications and processing conditions are stated in Table 2, below:
1 Machine Omega 40
2 Barrel Diameter 40 mm
3 Each Barrel length 160 mm
4 Total no. of Barrels 10
5 Total Length of Barrel 1600 mm
6 Side Inlet for PBAT C6
7 Machine L/D 40/40
8 Screw Speed 80 rpm
9 Screw Configuration As illustrated in Table 3
10 Feed Rate of blend comprising starch and glycerol 60 Kg/hr
11 Feed rate of PBAT 60 Kg/hr
12 Barrel temperature As illustrated in Table 4

Table 2: Machine specifications and processing conditions

The screw configuration of the twin screw extruder is provided in Table 3, below:
Sl. No Type of element* Quantity
1 RSC38/38 1
2 SKE 60/60 3
3 RSC38/38 3
4 RSC 50/50 1
5 RK 45/5-50 2
6 SKE 60/60 3
7 RSC 60/60 1
8 RSC 38/38 5
9 RK45/5-50 2
10 RSC 40/40 1
11 RSC60/60 1
12 SKE 60/60 1
13 RSC 60/60 2
14 RSC 50/50 4
15 SKE 60/60 2
16 RSC 38/38 4

Table 3: Screw Configuration
* List of Abbreviations for Elements
RSC Right-Handed Screw Element
SKE Schubkanten Element
RK Right-Handed Kneading Block

The temperature of barrels of the extruder is provided in Table 4, below:
Barrel No. C0 C1 C2 C3 C4 C5 C6 C7 C8 C9
Temperature (ºC±10ºC) 90 95 100 105 105 105 100 95 95 95

Table 4: Barrel Temperature
The properties of the biodegradable polymer composition (BPC1) obtained are summarized in Table 5, below:
S. No Name of Test Standard Followed Results
1 Tensile Strength, MPa ASTM D 638 10.25
2 Tensile Modulus, Mpa ASTM D 638 83
3 Elongation at break, % ASTM D 638 >300
4 Elongation at yield, % ASTM D 638 294.5
5 Flexural Strength, Mpa ASTM D 790 2.57
6 Flexural Modulus, Mpa ASTM D 790 75
7 Notched Izod Impact strength, KJ/m2 ASTM D 256 31.60
8 Heat deflection temperature at 0.455 Mpa, °C ASTM D648 49.1
9 Vicat Softening temperature , °C, [Load 10N at heating rate of 120°C/h] ASTM D 1525 75.2
10 MFI, g/10 min, [ At 190°C, 2.16 kg load] ASTM D 1238 10.9
11 Density, g/ cc ASTM D ASTM D 792 1.284

Table 5: Mechanical Properties of Biodegradable Polymer Composition
The thermogravimetric analysis of the obtained biodegradable polymer composition was conducted in a thermogravimetric analyser (Perkin Elmer TGA 4000) under a nitrogen atmosphere at a heating rate of 10oC per minute. The change in weight as a function of temperature was recorded. Figure 3 shows thermogravimetric analysis of the obtained biodegradable polymer composition. The thermogravimetric analysis shows two degradation peaks at temperatures of 329.10°C and 414.60°C.
Example 2: Comparison of the exemplary biodegradable polymer composition with prior art polymer disclosed in Can et al. (PBAT/thermoplastic starch blends: “Effects of oxidized starch and compatibilizer content; AIP Conference Proceedings 1914, 070004 (2017))

The mechanical properties of the exemplary biodegradable polymer composition (BPC1) prepared in Example 1 were compared with that of PBAT/thermoplastic starch blends disclosed in Can et al. Said PBAT/thermoplastic starch blend comprises PBAT and thermoplastic starch in a ratio of 50/50. Table 6 shows a comparison of the mechanical properties of biodegradable polymer composition with said prior art polymer.

Properties BPC1 Can et al. (50/50 PBAT/TPS)
Tensile Modulus, MPa 83 74.7
Tensile Strength, MPa 10.25 6.5
Notched Izod Impact Strength, kJ/m2 31.60
2.5
Elongation at break, % >300 17.7

Table 6: Comparison of mechanical properties

Observation: It was observed that the disclosed biodegradable polymer composition BPC1 exhibits significant improvement in mechanical properties when compared with prior known blends of PBAT and starch at same w/w ratio.

Example 3: Comparative study of mechanical properties of the biodegradable polymer composition with different amounts of modified starch

The process of Example 1 was followed using two commercially available PBAT ( from “Ecoworld” and “Xinjiang Blue Ridge Tunhe Polyester Co., Ltd (Tunhe)”) while maintaining the weight percentage of modified starch at 70% and 65% in the biodegradable polymer composition. Table 7, below summarizes the mechanical properties of the biodegradable polymer composition for said weight percentages of modified starch:

S. No Name of test 70% MS + 30% PBAT (Ecoworld)

70% MS + 30% PBAT (Tunhe)

65% MS + 35% PBAT (Tunhe)

1 MFI (g/10 min)(190°C & 2.16kg
_

3.02

4.06
2 a) Tensile strength (MPa)Speed of test -50mm/min 11.11 10.96 11.87
10.92 11.29 11.6
11.8 10.51 12.07
11.28 10.52 12.85
11.63 10.6 12.4
Mean   11.35 10.78 12.15
   
b) Tensile Modulus (MPa) 600 131 136
579 137 146
636 103 136
608 112 144
620 100 161
  Mean 608 117 145
c} Elongation @ yield (%) 8.28 285.45 299.52
8.38 289.56 298.62
8.28 291.24 289.58
8.08 285.42 299.64
8.33 288.56 289.52
Mean   8.27 288.04 295
d} Elongation @ break (%) 14.06 > 300 > 300
12.28 > 300 > 300
12.51 > 300 > 300
12.75 > 300 > 300
11.28 > 300 > 300
Mean 12.58 >300 > 300
3 Impact Strength (kJ/m2) 4.07 38.29 49.94
3.46 40.61 45.54
4.89 41.68 44.13
3.86 42.33 45.11
4.2 42.97 47.29
Mean   4.10 41.18 46.40
*MS: Modified Starch

Table 7: Comparison of mechanical properties
Observation: It was found that the biodegradable polymer composition with up to 70 % w/w of modified starch could be prepared with optimum set of mechanical properties.

Industrial Application

The disclosed biodegradable polymer composition finds application as a biodegradable plastic and is able to substitute polyethylene in the packaging industry, specifically in the food industry where single use plastics are used.

The disclosed biodegradable polymer composition uses higher proportions of starch (about 40% w/w or higher) with significant improvement in mechanical properties. The disclosed biodegradable polymer composition accordingly reduces cost.

The thermogravimetric analysis of disclosed biodegradable polymer composition shows a significant derivative weight loss % (greater than 1%) only at temperatures >300°C indicating a stable biodegradable polymer composition. Thus, the disclosed biodegradable polymer composition exhibits improved mechanical properties as well as thermal stability.
The SEM images of the disclosed biodegradable polymer composition illustrate that the composition shows a homogenous phase indicating better miscibility between the modified starch and PBAT. This allows subjecting the disclosed biodegradable polymer composition to different plastic processing technologies like blown film extrusion, blow molding, injection molding and thermoforming.
The disclosed biodegradable polymer composition is susceptible to both aerobic and anaerobic decomposition.