Biodegradable polyester and use thereof

Abstract

A biodegradable polyester and use thereof includes components: A) acid components containing following repeating units: 40 to 48 mol % of terephthalic acid A1; 38.5 to 50 mol % of sebacic acid A2; and 2 to 20 mol % of an aliphatic dibasic acid A3 with a carbon chain length of 6 or less; B) butanediol. In the case of low content of the terephthalic acid unit, by introducing the aliphatic dibasic acid unit with the carbon chain length of 6 or less, mechanical properties of the material can be significantly improved, and the mechanical property retention is better especially when stored in a humid environment.

Claims

1. A biodegradable polyester, comprising components as follows in mole percent: A) acid components containing following repeating units: 46 to 47.5 mol % of terephthalic acid A1; 45.5 to 50 mol % of sebacic acid A2; and 2.5 to 7 mol % of an aliphatic dibasic acid A3 with a carbon chain length of 6 or less; and B) butanediol.

2. The biodegradable polyester according to claim 1, wherein the aliphatic dibasic acid A3 with the carbon chain length of 6 or less is one of or a mixture of two or more of adipic acid, glutaric acid and succinic acid.

3. The biodegradable polyester according to claim 1, wherein the biodegradable polyester is made into a film of 25±1 μm, the film is processed at 40° C. and 85% relative humidity for one month, and a tensile property retention rate of the film tested by using ISO 527 standard is 65% or above.

4. A biodegradable polyester blend comprising the biodegradable polyester according to claim 1.

5. A preparation method of various film materials, comprising using the biodegradable polyester according to claim 1.

6. The preparation method of the various film materials according to claim 5, wherein the various film materials are biodegradable bags, mulching films, plastic wraps, or courier bags.

7. A biodegradable polyester blend comprising the biodegradable polyester according to claim 2.

8. A biodegradable polyester blend comprising the biodegradable polyester according to claim 3.

9. A preparation method of various film materials, comprising using the biodegradable polyester blend according to claim 4.

10. The preparation method of the various film materials according to claim 9, wherein the various film materials are biodegradable bags, mulching films, plastic wraps, or courier bags.

Description

DESCRIPTION OF THE EMBODIMENTS

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

(2) The raw materials used in the embodiments and comparative examples are all commercially available.

(3) Synthesis of Biodegradable Polyester:

(4) Under the protection of carbon dioxide, as shown in Table 1, sebacic acid, an aliphatic dibasic acid with a carbon chain length of 6 or less, and 1,4-butanediol which were measured were put into the reactor, and under stirring conditions, the temperature was raised to 200-210° C. for reaction for 1 hour, and then terephthalic acid and tetra-(2-ethylhexyl) titanate were added, the temperature was raised to 220-230° C. for reaction for 1-2 hours, vacuumization was conducted, and the pressure in the reactor was reduced to 100 Pa or less within 2 hours, reaction was conducted at 230-260° C. for 2-4 hours, stirring was stopped, the reactor was filled with carbon dioxide, the resin was extruded out of the reactor to be pelletized to obtain a biodegradable polyester. An amount of sebacic acid, an amount of the aliphatic dibasic acid with the carbon chain length of 6 or less, an amount of 1,4-butanediol and an amount of terephthalic acid can be changed to obtain resins with different structures.

(5) Property Evaluation Method:

(6) Melt flow index: test condition is 190° C., 2.16 Kg counter weight.

(7) Film tensile test method: the biodegradable polyester was made into a film of 25±1 μm, and then was tested by using ISO 527 standard.

(8) Tensile property retention rate: the film was processed at 40° C. and 85% relative humidity for one month, and the initial tensile property and the tensile property after processing were tested. Tensile property retention rate=tensile property after processing/initial tensile property.

(9) Property results are shown in Table 2 and Table 3.

(10) TABLE-US-00001 TABLE 1 Mass of each raw material in embodiments and comparative examples sebacic 1,4-butanediol terephthalic tetra-(2-ethylhexyl) adipic glutaric succinic acid (g) (g) acid (g) titanate (g) acid (g) acid (g) acid (g) Embodiment 1 2551.4 3410.6 1991.0 6.0 92.2 Embodiment 2 2491.3 2433.3 1983.1 6.0 151.0 Embodiment 3 2328.6 3458.7 1912.8 6.0 373.9 Embodiment 4 2138.2 3572.9 1932.0 6.0 499.4 Embodiment 5 2054.6 3521.2 1774.2 6.0 761.3 Embodiment 6 2042.2 3500.0 2064.6 6.0 491.9 Comparative 2663.3 3390.6 1979.3 6.0 Example 1 Comparative 2825.9 3372.8 1823.8 6.0 Example 2 Comparative 2963.9 3357.7 1691.8 6.0 Example 3

(11) TABLE-US-00002 TABLE 2 Mole content of each unit of embodiments and comparative examples terephthalic sebacic adipic glutaric succinic acid acid acid acid acid content content content content content (mol %) (mol %) (mol %) (mol %) (mol %) Embodiment 1 47.5 50.0 2.50 Embodiment 2 47.0 48.5 4.50 Embodiment 3 45.0 45.0 10.0 Embodiment 4 44.0 40.0 16.0 Embodiment 5 41.0 39.0 20.0 Embodiment 6 48.0 39.0 13.0 Comparative 47.5 52.5 Example 1 Comparative 44.0 56.0 Example 2 Comparative 41.0 59.0 Example 3

(12) TABLE-US-00003 TABLE 3 Results of property tests of embodiments and comparative examples Initial Initial Longitudinal Longitudinal Transverse Transverse Melt flow longitudinal transverse tensile tensile property tensile tensile property index tensile tensile strength after retention strength after retention g/10 min strength/Mpa strength/Mpa processing/Mpa rate/% processing/Mpa rate/% Embodiment 1 6.2 26.5 27 21.6 81.5 22.7 84.07 Embodiment 2 6.4 25.7 26.4 21.2 82.49 22.5 85.23 Embodiment 3 6.0 27.2 26.7 20.4 75 20.5 76.78 Embodiment 4 6.2 26.2 27.1 19.9 75.95 19.6 72.32 Embodiment 5 6.1 24.5 23.6 17.8 72.65 18.1 76.69 Embodiment 6 6.3 26.9 28.3 20.1 74.72 19.3 68.2 Comparative 6.2 24.9 25.4 13.2 53.01 13.5 53.15 Example 1 Comparative 6.2 23.9 24.2 11.3 47.28 12.1 50 Example 2 Comparative 6.1 20.3 21.4 8.8 43.35 10.2 47.66 Example 3

(13) As can be seen from the results of the embodiments and comparative examples in Table 3, the present invention can significantly improve mechanical properties of the material by introducing the aliphatic dibasic acid unit with the carbon chain length of 6 or less, and the mechanical property retention rate can reach more than 65% when stored in a humid environment.