Biodegradable polyester composition and use thereof

Abstract

The present invention discloses a biodegradable polyester composition, wherein the biodegradable polyester composition comprises the following components in parts by weight: i) 58 to 80 parts by weight of an aliphatic-aromatic copolyester; ii) 20 to 32 parts by weight of starch; and iii) 0 to 10 parts by weight of a processing agent. The present invention unexpectedly found by research that by using an aliphatic-aromatic copolyester in which an amount of aromatic carboxylic acid accounts for a total amount of diacid is 44 mol % to 48 mol % as a matrix resin, where the aliphatic-aromatic copolyester has a crystallization peak width D of 5° C. to 16° C., and by using starch of which a particle size D (50) is 2 μm to 12 μm as the other phase, and meanwhile by adding a specific amount of a processing agent, the polyester composition prepared has excellent transversal and longitudinal tear strengths, and the polyester composition has a biodegradation rate of 90% or more during the 12-week degradation test, satisfying the industrial compost.

Claims

1. A biodegradable polyester composition, comprising: i) 58 to 80 parts by weight of an aliphatic-aromatic copolyester; ii) 20 to 32 parts by weight of starch; and iii) 0 to 10 parts by weight of a processing agent wherein in the component ii), the starch has a particle size D (50) of 2 μm to 12 μm, wherein as for the component i), in the aliphatic-aromatic copolyester, an amount of aromatic carboxylic acid accounts for 44 mol % to 48 mol % of a total amount of diacid, and a crystallization peak width D of the aliphatic-aromatic copolyester is 5° C. to 16° C., wherein in the component i), the aliphatic-aromatic copolyester is selected from one or a mixture of poly(butyleneadipate-co-terephthalate) (PBAT) and poly(butylene sebacate-co-terephthalate) (PBSeT).

2. The biodegradable polyester composition according to claim 1, wherein the biodegradable polyester composition comprises the following components in parts by weight: i) 62 to 80 parts by weight of the aliphatic-aromatic copolyester; ii) 20 to 30 parts by weight of starch; and iii) 0 to 8 parts by weight of the processing agent.

3. The biodegradable polyester composition according to claim 1, wherein a 12μm ±1μm film prepared by the polyester composition has a longitudinal tear strength, which is tested according to the standard ASTM D-882/88, of 1000 mN or more; the 12μm±1μm film prepared by the polyester composition has a transversal tear strength, which is tested according to the standard ASTM D-882/88, of 2400 mN or more; the 12μm ±1μm film prepared by the polyester composition has an post-12-week biodegradation rate of more than 90% which is tested according to the standard ISO 16929 (2013).

4. The biodegradable polyester composition according to claim 1, wherein the processing agent is selected from one or more of water, glycerin, polyglycerin, epoxy soybean oil, citrate, acetyl citrate, ethylene glycol, and polyethylene glycol.

5. The biodegradable polyester composition according to claim 1, wherein the biodegradable polyester composition further comprises 0 to 20 parts by weight of an organic filler or an inorganic filler.

6. The biodegradable polyester composition according to claim 5, wherein the organic filler is selected from one or more of natural fiber, straw and wood powder; and the inorganic filler is selected from one or a mixture of more or talcum powder, montmorillonite, kaolin, chalk, calcium carbonate, graphite, gypsum, conductive carbon black, calcium chloride, iron oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber and mineral fiber.

7. The biodegradable polyester composition according to claim 2, wherein a 12μm±1μm film prepared by the polyester composition has a longitudinal tear strength, which is tested according to the standard ASTM D-882/88, of 1000 mN or more; the 12μm±1μm film prepared by the polyester composition has a transversal tear strength, which is tested according to the standard ASTM D-882/88, of 2400 mN or more; the 12μm±1μm film prepared by the polyester composition has an post-12-week biodegradation rate of more than 90% which is tested according to the standard ISO 16929 (2013).

8. The biodegradable polyester composition according to claim 2, wherein the processing agent is selected from one or more of water, glycerin, polyglycerin, epoxy soybean oil, citrate, acetyl citrate, ethylene glycol, and polyethylene glycol.

9. The biodegradable polyester composition according to claim 2, wherein the biodegradable polyester composition further comprises 0 to 20 parts by weight of an organic filler or an inorganic filler.

10. The biodegradable polyester composition according to claim 9, wherein the organic filler is selected from one or a mixture of more of natural fiber, straw and wood powder; and the inorganic filler is selected from one or more or talcum powder, montmorillonite, kaolin, chalk, calcium carbonate, graphite, gypsum, conductive carbon black, calcium chloride, iron oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber and mineral fiber.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(1) The present invention is further described by the following specific implementations. The following embodiments are the preferable implementations of the present invention, but the implementation of the present invention is not limited thereto.

(2) Raw materials used by Embodiments and Comparative Examples of the present invention are as follows.

(3) The component i) was selected from:

(4) PBAT-1: an amount of aromatic carboxylic acid accounting for 46 mol % of a total amount of diacid, a crystallization peak width D of 11° C.;

(5) PBAT-2: an amount of aromatic carboxylic acid accounting for 44 mol % of a total amount of diacid, a crystallization peak width D of 8° C.;

(6) PBAT-3: an amount of aromatic carboxylic acid accounting for 48 mol % of a total amount of diacid, a crystallization peak width D of 15° C.;

(7) PBAT-4: an amount of aromatic carboxylic acid accounting for 38 mol % of a total amount of diacid, a crystallization peak width D of 11° C.;

(8) PBAT-5: an amount of aromatic carboxylic acid accounting for 58 mol % of a total amount of diacid, a crystallization peak width D of 11° C.;

(9) PBAT-6: an amount of aromatic carboxylic acid accounting for 46 mol % of a total amount of diacid, a crystallization peak width D of 4° C.;

(10) PBAT-7: an amount of aromatic carboxylic acid accounting for 46 mol % of a total amount of diacid, a crystallization peak width D of 25° C.;

(11) PBAT-8: an amount of aromatic carboxylic acid accounting for 58 mol % of a total amount of diacid, a crystallization peak width D of 25° C.; and

(12) PBSeT: an amount of aromatic carboxylic acid accounting for 46 mol % of a total amount of diacid, a crystallization peak width D of 11° C.

(13) The component ii) was selected from:

(14) Starch-1, particle size D (50) of 4 μm;

(15) Starch-2, particle size D (50) of 8 μm;

(16) Starch-3, particle size D (50) of 12 μm;

(17) Starch-4, particle size D (50) of 16 μm; and

(18) Starch-5, particle size D (50) of 1 μm.

(19) The component iii) was selected from the following processing agent: water, glycerin.

(20) The fillers were selected from: talcum powder, calcium carbonate.

(21) Other additives:

(22) citrate was selected as a plasticizer; palmitate was selected as a surfactant; and

(23) other components were all commercially available.

(24) Evaluation Methods for Each Performance Index:

(25) Test method for crystallization peak width D of the aliphatic-aromatic copolyester:

(26) by testing via the differential scanning calorimeter (DSC), specific test method is as follows: high-purity reference substance (indium) was used to calibrate the differential scanning calorimeter, 5 to 10 mg of aliphatic-aromatic copolyester was put into an aluminum-made crucible, heated to 220° C. at a rate of 10° C./min (the first scanning), kept at constant temperature for 5 minutes, and cooled to −30° C. at a rate of 10° C./min. A crystallization peak of the aliphatic-aromatic copolyester was obtained from a cooling curve in the differential analysis graph of the first scanning. The start terminal and the end terminal of the crystallization peak were taken to make tangent lines, and a temperature difference of the end points of the two tangent lines is the crystallization peak width.

(27) Test method for particle size D (50) of starch:

(28) the test method for particle size D (50) of starch in the present invention was performed referring to the method of GB/T 19077.1 Particle Size Analysis—Laser Diffraction Method.

(29) Longitudinal and transversal tear strengths of the polyester composition were obtained by that: the polyester composition was made into a 12 μm±1 μm film which was subjected to the test according to standard ASTM D-882/88.

(30) Post-12-week biodegradation rate of the polyester composition was obtained by that: the polyester composition was made into a 12 μm±1 μm film which was subjected to the test according to standard ISO 16929 (2013).

Embodiments 1-11 and Comparative Examples 1-4

(31) According to the proportion of parts by weight in Table 1, the aliphatic-aromatic copolyester, starch, processing agents, fillers and other additives were mixed evenly and added to a single-screw extruder, extruded at 140° C.-240° C. and pelletized to obtain a biodegradable polyester composition. Test data for each performance of the obtained polyester composition is shown as Table 1.

(32) TABLE-US-00001 TABLE 1 Proportion of each component and performance test results of the embodiments and comparative examples (part by weight) Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Comparative Comparative Comparative Comparative Component ment 1 ment 2 ment 3 ment 4 ment 5 ment 6 ment 7 ment 8 ment 9 ment 10 ment 11 Example 1 Example 2 Example 3 Example 4 Aliphatic- PBAT-1 70 50 90 70 70 aromatic PBAT-2 70 70 copolyes- PBAT-3 ter PBAT-4 70 PBAT-5 70 PBAT-6 70 PBAT-7 70 PBAT-8 70 70 70 PBSeT 70 Starch Starch-1 25 25 25 10 40 Starch-2 25 Starch-3 25 25 25 25 25 25 25 Starch-4 25 Starch-5 25 Process- Water 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 ing agent Glycerin 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Filler Talcum 2 2 2 2 2 2 2 2 2 powder Calcium 2 2 2 2 2 2 carbonate Other Plasticizer 0.1 0.1 0.1 0.1 0.1 0.1 Additive Surfactant 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Longitudinal 1098 1273 1156 1063 989 963 952 921 889 867 844 782 801 712 698 tear strength Transversal 2793 3123 2901 2682 2374 2263 2193 2223 2102 2011 2000 1912 1908 1954 1783 tear strength Post-12-week 96.7 98.3 97.1 96.2 95.3 94.2 93.6 93.1 92.4 91.2 91.1 90.7 90.4 90.1 90.3 biodegradation rate (%)