Biodegradable polyester composition

Abstract

A biodegradable polyester composition based on a total weight of the biodegradable polyester composition, including a weight content of tetrahydrofuran, which is 3 ppm-200 ppm; and based on the total weight of the biodegradable polyester composition, a weight content of cyclopentanone is 0.5 ppm-85 ppm is provided. The tetrahydrofuran and cyclopentanone is added into the composition and controlling the content of tetrahydrofuran and the content of cyclopentanone in a certain range in the composition to realize printing performance. Moreover, when a velocity of film blowing is 176 Kg/h, a range of a film thickness is less than 0.2 m and a relative deviation of the film thickness is less than 1%.

Claims

1. A biodegradable polyester composition, comprising the following components in parts by weight: i) 60 to 100 parts of biodegradable aliphatic-aromatic polyester; ii) 0 to 40 parts of polylactic acid; iii) 0 to 35 parts of an organic filler and/or an inorganic filler; iv) 0 to 1 part of a copolymer which contains epoxy group and is based on styrene, acrylate and/or methacrylate; wherein, based on a total weight of the biodegradable polyester composition, a weight content of tetrahydrofuran is 3 ppm-200 ppm; and based on the total weight of the biodegradable polyester composition, a weight content of cyclopentanone is 0.5 ppm-85 ppm.

2. The biodegradable polyester composition according to claim 1, wherein based on the total weight of the biodegradable polyester composition, the weight content of tetrahydrofuran is 8 ppm-100 ppm; and the weight content of cyclopentanone is 5 ppm-50 ppm.

3. The biodegradable polyester composition according to claim 1, comprising the following components in parts by weight: i) 65 to 95 parts of the biodegradable aliphatic-aromatic polyester; ii) 5 to 35 parts of the polylactic acid; iii) 5 to 25 parts of the organic filler and/or the inorganic filler; iv) 0.02 to 0.5 part of the copolymer which contains epoxy group and is based on styrene, acrylate and/or methacrylate.

4. The biodegradable polyester composition according to claim 1, wherein the weight content of tetrahydrofuran is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of tetrahydrofuran in the biodegradable polyester composition is measured by a static headspace method; the content of tetrahydrofuran in the biodegradable polyester composition is calculated according to the peak area of tetrahydrofuran in the biodegradable polyester composition and a standard curve of tetrahydrofuran; and the standard curve of tetrahydrofuran is calibrated by a solution of tetrahydrofuran/methanol; the weight content of cyclopentanone is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of cyclopentanone in the biodegradable polyester composition is measured by the static headspace method; the content of cyclopentanone in the biodegradable polyester composition is calculated according to the peak area of cyclopentanone in the biodegradable polyester composition and a standard curve of cyclopentanone; and the standard curve of cyclopentanone is calibrated by a solution of cyclopentanone/methanol.

5. The biodegradable polyester composition according to claim 1, wherein the biodegradable aliphatic-aromatic polyester is one or more of poly(butyleneadipate-co-terephthalate) (PBAT), poly(butylenesuccinate-co-terephthalate) (PBST) and poly(butylenesebacate-co-terephthalate) (PBSeT).

6. The biodegradable polyester composition according to claim 1, wherein the organic filler is selected from a group consisting of natural starch, plasticized starch, modified starch, natural fiber and wood flour, or a mixture thereof; and the inorganic filler is selected from a group consisting of talcum powder, montmorillonite, kaolin, chalk, calcium carbonate, graphite, gypsum, conductive carbon black, calcium chloride, ferric oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber and mineral fiber, or a mixture thereof.

7. The biodegradable polyester composition according to claim 1, further comprising 0 to 4 parts of at least one of following substances: plasticizer, release agent, surfactant, wax, antistatic agent, pigment, UV absorbent, UV stabilizer or other plastic additives.

8. The biodegradable polyester composition according to claim 1, wherein a level of printing performance of the biodegradable polyester composition reaches to level 3 or above.

9. The biodegradable polyester composition according to claim 1, wherein when an extrusion velocity at film blowing of the biodegradable polyester composition is 176 Kg/h, a range of a film thickness is less than 0.2 m and a relative deviation of the film thickness is less than 1%.

10. The biodegradable polyester composition according to claim 2, comprising the following components in parts by weight: i) 65 to 95 parts of the biodegradable aliphatic-aromatic polyester; ii) 5 to 35 parts of the polylactic acid; iii) 5 to 25 parts of the organic filler and/or the inorganic filler; iv) 0.02 to 0.5 part of the copolymer which contains epoxy group and is based on styrene, acrylate and/or methacrylate.

11. The biodegradable polyester composition according to claim 2, wherein the weight content of tetrahydrofuran is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of tetrahydrofuran in the biodegradable polyester composition is measured by a static headspace method; the content of tetrahydrofuran in the biodegradable polyester composition is calculated according to the peak area of tetrahydrofuran in the biodegradable polyester composition and a standard curve of tetrahydrofuran; and the standard curve of tetrahydrofuran is calibrated by a solution of tetrahydrofuran/methanol; the weight content of cyclopentanone is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of cyclopentanone in the biodegradable polyester composition is measured by the static headspace method; the content of cyclopentanone in the biodegradable polyester composition is calculated according to the peak area of cyclopentanone in the biodegradable polyester composition and a standard curve of cyclopentanone; and the standard curve of cyclopentanone is calibrated by a solution of cyclopentanone/methanol.

12. The biodegradable polyester composition according to claim 3, wherein the weight content of tetrahydrofuran is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of tetrahydrofuran in the biodegradable polyester composition is measured by a static headspace method; the content of tetrahydrofuran in the biodegradable polyester composition is calculated according to the peak area of tetrahydrofuran in the biodegradable polyester composition and a standard curve of tetrahydrofuran; and the standard curve of tetrahydrofuran is calibrated by a solution of tetrahydrofuran/methanol; the weight content of cyclopentanone is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of cyclopentanone in the biodegradable polyester composition is measured by the static headspace method; the content of cyclopentanone in the biodegradable polyester composition is calculated according to the peak area of cyclopentanone in the biodegradable polyester composition and a standard curve of cyclopentanone; and the standard curve of cyclopentanone is calibrated by a solution of cyclopentanone/methanol.

13. The biodegradable polyester composition according to claim 10, wherein the weight content of tetrahydrofuran is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of tetrahydrofuran in the biodegradable polyester composition is measured by a static headspace method; the content of tetrahydrofuran in the biodegradable polyester composition is calculated according to the peak area of tetrahydrofuran in the biodegradable polyester composition and a standard curve of tetrahydrofuran; and the standard curve of tetrahydrofuran is calibrated by a solution of tetrahydrofuran/methanol; the weight content of cyclopentanone is measured by following method: 1.2000 g of the biodegradable polyester composition is weighed accurately and added into a static headspace test flask; a peak area of cyclopentanone in the biodegradable polyester composition is measured by the static headspace method; the content of cyclopentanone in the biodegradable polyester composition is calculated according to the peak area of cyclopentanone in the biodegradable polyester composition and a standard curve of cyclopentanone; and the standard curve of cyclopentanone is calibrated by a solution of cyclopentanone/methanol.

14. The biodegradable polyester composition according to claim 2, wherein the biodegradable aliphatic-aromatic polyester is one or more of poly(butyleneadipate-co-terephthalate) (PBAT), poly(butylenesuccinate-co-terephthalate) (PB ST) and poly(butylenesebacate-co-terephthalate) (PBSeT).

15. The biodegradable polyester composition according to claim 3, wherein the biodegradable aliphatic-aromatic polyester is one or more of poly(butyleneadipate-co-terephthalate) (PBAT), poly(butylenesuccinate-co-terephthalate) (PBST) and poly(butylenesebacate-co-terephthalate) (PBSeT).

16. The biodegradable polyester composition according to claim 10, wherein the biodegradable aliphatic-aromatic polyester is one or more of poly(butyleneadipate-co-terephthalate) (PBAT), poly(butylenesuccinate-co-terephthalate) (PBST) and poly(butylenesebacate-co-terephthalate) (PBSeT).

17. The biodegradable polyester composition according to claim 2, wherein the organic filler is selected from a group consisting of natural starch, plasticized starch, modified starch, natural fiber and wood flour, or a mixture thereof; and the inorganic filler is selected from a group consisting of talcum powder, montmorillonite, kaolin, chalk, calcium carbonate, graphite, gypsum, conductive carbon black, calcium chloride, ferric oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber and mineral fiber, or a mixture thereof.

18. The biodegradable polyester composition according to claim 3, wherein the organic filler is selected from a group consisting of natural starch, plasticized starch, modified starch, natural fiber and wood flour, or a mixture thereof; and the inorganic filler is selected from a group consisting of talcum powder, montmorillonite, kaolin, chalk, calcium carbonate, graphite, gypsum, conductive carbon black, calcium chloride, ferric oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber and mineral fiber, or a mixture thereof.

19. The biodegradable polyester composition according to claim 10, wherein the organic filler is selected from a group consisting of natural starch, plasticized starch, modified starch, natural fiber and wood flour, or a mixture thereof; and the inorganic filler is selected from a group consisting of talcum powder, montmorillonite, kaolin, chalk, calcium carbonate, graphite, gypsum, conductive carbon black, calcium chloride, ferric oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber and mineral fiber, or a mixture thereof.

20. The biodegradable polyester composition according to claim 2, further comprising 0 to 4 parts of at least one of following substances: plasticizer, release agent, surfactant, wax, antistatic agent, pigment, UV absorbent, UV stabilizer or other plastic additives.

21. The biodegradable polyester composition according to claim 3, further comprising 0 to 4 parts of at least one of following substances: plasticizer, release agent, surfactant, wax, antistatic agent, pigment, UV absorbent, UV stabilizer or other plastic additives.

22. The biodegradable polyester composition according to claim 10, further comprising 0 to 4 parts of at least one of following substances: plasticizer, release agent, surfactant, wax, antistatic agent, pigment, UV absorbent, UV stabilizer or other plastic additives.

23. The biodegradable polyester composition according to claim 2, wherein a level of printing performance of the biodegradable polyester composition reaches to level 3 or above.

24. The biodegradable polyester composition according to claim 4, wherein a level of printing performance of the biodegradable polyester composition reaches to level 3 or above.

25. The biodegradable polyester composition according to claim 11, wherein a level of printing performance of the biodegradable polyester composition reaches to level 3 or above.

26. The biodegradable polyester composition according to claim 2, wherein when an extrusion velocity at film blowing of the biodegradable polyester composition is 176 Kg/h, a range of a film thickness is less than 0.2 m and a relative deviation of the film thickness is less than 1%.

27. The biodegradable polyester composition according to claim 4, wherein when an extrusion velocity at film blowing of the biodegradable polyester composition is 176 Kg/h, a range of a film thickness is less than 0.2 m and a relative deviation of the film thickness is less than 1%.

28. The biodegradable polyester composition according to claim 11, wherein when an extrusion velocity at film blowing of the biodegradable polyester composition is 176 Kg/h, a range of a film thickness is less than 0.2 m and a relative deviation of the film thickness is less than 1%.

29. The biodegradable polyester composition according to claim 1, wherein based on the total weight of the biodegradable polyester composition, the weight content of tetrahydrofuran is 15 ppm-75 ppm; and the weight content of cyclopentanone is 10 ppm-35 ppm.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(1) The present invention will be further described below by way of specific implementations, and 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) In the embodiments of the present invention, PBAT is chosen as a component i); ADR4370 is chosen as a component iv); starch is chosen as an organic filler; talcum powder and calcium carbonate are chosen as inorganic filler; citric esters is chosen as a plasticizer; palmitate is chosen as a surfactant; and stearamide is chosen as a wax. The above-mentioned promoters, PBAT, ADR4370, PLA, tetrahydrofuran and cyclopentanone are commercially available.

Embodiments 1-16 and Comparative Embodiments 1-4

(3) According to formulae shown in Table 1, PBAT, PLA, ADR4370, organic fillers, inorganic fillers, promoters such as plasticizer, surfactant, wax and the like, tetrahydrofuran and cyclopentanone were mixed evenly and put into a single screw extruder. After being extruded at 140 C.-240 C. and prilled, the compositions were obtained. Data of performance tests is shown in Table 1.

(4) Performance Evaluation Method:

(5) (1) Evaluation Method for Printing Performance of a Biodegradable Polyester Composition:

(6) Biodegradable polyester compositions with different printing effects were taken. Based on clarity of a printed label and adherence of ink to a surface of a film, different printing effects were ranked according to following method:

(7) level 1: the label is clear and there is no excessive ink adhering to the film;

(8) level 2: the label is clear but there is a little excessive ink adhering to the film;

(9) level 3: the label is basically clear but there is much ink adhering to the film;

(10) level 4: the label is obscure and there is abundant ink adhering to the film;

(11) level 5: the label can't be shown and there is no ink adhering to the film.

(12) (2) Evaluation Method for Bubble Stability of the Biodegradable Polyester Composition:

(13) The bubble stability of the biodegradable polyester composition during film blowing was evaluated by a method of a range of a film thickness and a relative deviation of the film thickness:

(14) The film thickness was measured via a screw micrometer: 10 measurement points were taken evenly on a film of 1 m*1 m to measure the film thickness.

(15) The range of the film thickness was a difference value between a maximum thickness and a minimum thickness among the 10 measurement points.

(16) The relative deviation of the film thickness was calculated according to the following formula:

(17) $\mathrm{relative}\mathrm{deviation}\mathrm{of}\mathrm{film}\mathrm{thickness}\%=\frac{\mathrm{range}\mathrm{of}\mathrm{film}\mathrm{thickness}}{\mathrm{average}\mathrm{film}\mathrm{thickness}}100\%$

(18) wherein, the average film thickness was calculated as an arithmetic average of the thicknesses measured respectively at the 10 measurement points which were taken evenly on the film of 1 m*1 m.

(19) (3) Determination Method for Tetrahydrofuran:

(20) Drawing of a Standard Curve of Tetrahydrofuran:

(21) Tetrahydrofuran/methanol solutions in concentrations of 0.010 g/L, 0.1 g/L, 1.0 g/L, 5.0 g/L, 10.0 g/L, 20.0 g/L, 50.0 g/L and 100.0 g/L were prepared, respectively. Peak areas of tetrahydrofuran in the tetrahydrofuran/methanol solutions in different concentrations were measured respectively by a static headspace method. The standard curve of tetrahydrofuran was drawn, with the peak area of tetrahydrofuran as an ordinate and the concentration of tetrahydrofuran as an abscissa.

(22) Measurement of a Content of Tetrahydrofuran in the Biodegradable Polyester Composition:

(23) Approximate 1.2000 g of biodegradable polyester composition was weighed accurately and put into a static headspace test flask; the peak area of tetrahydrofuran in the biodegradable polyester composition was measured by the static headspace method; and the content of tetrahydrofuran in the biodegradable polyester composition was calculated according to the peak area of tetrahydrofuran in the biodegradable polyester composition and the standard curve of tetrahydrofuran. The standard curve was calibrated by the tetrahydrofuran/methanol solution.

(24) Conditions for Static Headspace Test are as Follows:

(25) Temperature:

(26) Heater: 105 C.

(27) Quantitative loop: 135 C.

(28) Transmission line: 165 C.

(29) Time:

(30) Balance for sample bottle: 120 minutes

(31) Duration for sample injection: 0.09 minute

(32) GC circulation: 30 minutes.

(33) Instrument models and parameters for static headspace are as follows:

(34) Agilent Technologies 7697 Headspace Sampler;

(35) Agilent Technologies 7890 AGC System;

(36) Chromatographic column: J&W 122-7032: 250 C.: 30 m250 m0.25 m

(37) Sample injection: front SS injection port N.sub.2

(38) Sample production: front detector FID.

(39) (4) Determination Method for Cyclopentanone:

(40) 1) Drawing of a Standard Curve of Cyclopentanone:

(41) Cyclopentanone/methanol solutions in concentrations of 0.0001 g/L, 0.001 g/L, 0.01 g/L, 0.1 g/L, 5.0 g/L, 10.0 g/L and 20.0 g/L were prepared, respectively. Peak areas of cyclopentanone in the cyclopentanone/methanol solutions in different concentrations were measured respectively by the static headspace method. The standard curve of cyclopentanone was drawn, with the peak area of cyclopentanone as the ordinate and the concentration of cyclopentanone as the abscissa.

(42) 2) Measurement of a Content of Cyclopentanone in the Biodegradable Polyester Composition:

(43) Approximate 1.2000 g of biodegradable polyester composition was weighed accurately and put into a static headspace test flask; the peak area of cyclopentanone in the biodegradable polyester composition was measured by the static headspace method; and the content of cyclopentanone in the biodegradable polyester composition was calculated according to the peak area of cyclopentanone in the biodegradable polyester composition and the standard curve of cyclopentanone.

(44) Instrument models and parameters for static headspace are as follows:

(45) Agilent Technologies 7697 Headspace Sampler;

(46) Agilent Technologies 7890A GC System;

(47) Chromatographic column: J&W 122-7032: 250 C.: 30 m250 m0.25 m

(48) Sample injection: front SS injection port N.sub.2

(49) Sample production: front detector FID.

(50) Conditions for static headspace test are as follows:

(51) Temperature:

(52) Heater: 105 C.

(53) Quantitative loop: 135 C.

(54) Transmission line: 165 C.

(55) Time:

(56) Balance for sample bottle: 120 minutes

(57) Duration for sample injection: 0.09 minute

(58) GC circulation: 30 minutes.

(59) TABLE-US-00001 TABLE 1 Test data of Comparative Embodiments 1-4 and Embodiments 1-16 (parts by weight) Compar- Compar- Compar- Compar- ative ative ative ative Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- ment 1 ment 2 ment 3 ment 4 ment 1 ment 2 ment 3 ment 4 ment 5 ment 6 ment 7 PBAT 84.1 84.1 84.1 84.1 100 84.1 84.1 84.1 84.1 67 66.5 PLA 10 10 10 10 10 10 10 10 15 32 starch 17 talcum powder 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 calcium carbonate 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 ADR4370 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.5 citric esters 0.2 palmitate 0.5 stearamide 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 content of tetra- 1 227 15 81 200 15 19 21 38 44 75 hydrofuran (based on the whole composition)/ppm content of cyclo- 0 117 10 38 10 10 12 17 23 30 35 pentanone (based on the whole composition)/ppm level of printing 4 5 2 2 3 1 1 1 1 1 1 performance extrusion 176 176 125 200 176 176 176 176 176 176 176 velocity at film blowing/Kg/h range of film 0.31 0.42 0.21 0.29 0.19 0.10 0.10 0.14 0.15 0.13 0.15 thickness/m relative devia- 1.5 2.1 1.12 1.93 0.92 0.42 0.43 0.55 0.61 0.62 0.69 tion of film thickness/% Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- ment 9 ment 10 ment 11 ment 12 ment 13 ment 14 ment 15 ment 16 PBAT 84.1 84.1 84.1 84.1 84.1 84.1 84.1 84.1 PLA 10 10 10 10 10 10 10 10 starch talcum powder 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 calcium carbonate 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 ADR4370 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 citric esters palmitate stearamide 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 content of tetra- 8 12 81 100 3 5 167 200 hydrofuran (based on the whole composition)/ppm content of cyclo- 6 8 38 50 1 4 62 85 pentanone (based on the whole composition)/ppm level of printing 2 2 2 2 3 3 3 3 performance extrusion 176 176 176 176 176 176 176 176 velocity at film blowing/Kg/h range of film 0.16 0.15 0.17 0.17 0.19 0.18 0.19 0.19 thickness/m relative devia- 0.81 0.74 0.83 0.84 0.98 0.89 0.90 0.95 tion of film thickness/%

(60) It can be seen from Table 1 that, in the biodegradable polyester composition, when the content of tetrahydrofuran is 3-200 ppm and the content of cyclopentanone is 0.5-85 ppm, the level of printing performance can reach above level 3, which indicates that the composition has excellent printing performance. In addition, when the velocity at film blowing is 176 Kg/h, the range of the film thickness is less than 0.2 m and the relative deviation of the film thickness is less than 1%. It indicates that the composition has better bubble stability. However, in Comparative Embodiment 1, in which the content of tetrahydrofuran is less than 3 ppm and the content of cyclopentanone is 0, the level of printing performance of the composition is level 4, the range of the film thickness is more than 0.2 m, and the relative deviation of the film thickness is more than 1%. In Comparative Embodiment 2, in which the content of tetrahydrofuran is more than 200 ppm and the content of cyclopentanone is more than 85 ppm, the level of printing performance of the composition is level 5, the range of the film thickness is more than 0.2 m, and the relative deviation of the film thickness is more than 1%, which indicates that the printing performance and the bubble stability of the composition are rather poor. In Comparative Embodiment 3, in which the velocity at film blowing is lower than 176 Kg/h and in Comparative Embodiment 4, in which the velocity at film blowing is higher than 176 Kg/h, the range of the film thickness is more than 0.2 m and the relative deviation of the film thickness is more than 1%. It indicates that the film bubble of the composition is unstable either.