A method for preparing degradable toughened polyester elastomers and blended polymer alloys

Abstract

The application relates to a preparation method of a degradable toughened polyester elastomer and a blended polymer alloy, which comprises the following steps: preparing the degradable toughened polyester elastomer by melt esterification and polycondensation of a hydroxyl-terminated PGA oligomer and a dibasic acid; the molecular weight of the hydroxyl-terminated PGA oligomer is 400-7000 g / mol; the dibasic acid is an aliphatic linear dibasic acid or a flexible alicyclic diacid with 2-12 carbon atoms; drying and uniformly mixing PGA and the degradable toughened polyester elastomer, and then blending and extruding in a double-screw extruder to obtain a PGA / PGA-based elastomer blended polymer alloy. The degradable toughened polyester elastomer prepared by the application balances the tensile strength and the elongation at break, and solves the problem that the degradation performance and the mechanical performance of a conventional polyglycolide copolyester cannot be compatible; the PGA-based elastomer is used to modify PGA to prepare the blended polymer alloy, the two phases have good compatibility, the process is simple, and the blended polymer alloy has high tensile strength and toughness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and relates to a preparation method of a degradable toughened polyester elastomer and a blended polymer alloy. BACKGROUND

[0002] Plastics are widely used due to their low cost and strong processability. However, many plastic products cannot be degraded in the natural environment after use, which seriously damages the ecological environment. Using biodegradable materials to replace some petroleum-based non-degradable plastics, especially disposable plastic products, can effectively reduce plastic garbage in the environment. With the development of technology, many biodegradable materials have reached the scale of industrialization, such as polylactic acid (PLA) and polyglycolide (PGA). However, these materials are brittle, and the application scenarios are limited by mechanical properties.

[0003] Introducing flexible segments through copolymerization is a common method to improve the toughness of polymers. Patent CN 103910860 A prepares glycolic acid copolyester through a three-step synthesis process. First, glycolic acid, adipic acid and ethylene glycol are added to the reactor in proportion for pre-polycondensation. The pre-polymer product is further polycondensed to obtain a medium molecular weight glycolic acid copolyester and is crushed. Finally, the crushed glycolic acid copolyester is subjected to solid-phase polycondensation. The glycolic acid copolymer obtained by the process has a lower melting point than PGA and better thermal processing performance, but the preparation process is complicated, and the adipic acid-ethylene glycol segment generated during the polymerization process is not degradable, thereby affecting the degradation performance of the copolymer. Patent CN 109438682 A discloses a copolyester and a preparation method thereof, specifically a preparation method of a furandicarboxylic acid, butanediol and glycolic acid block copolyester material. First, furandicarboxylic acid-butanediol oligomers and glycolic acid oligomers are prepared, respectively, and then co-polycondensation is performed. The obtained copolyester has good elongation at break (220%). However, the degradation performance of the furandicarboxylic acid-butanediol oligomer is poor, which reduces the degradation performance of the copolyester. Patent CN 117343293 A provides a preparation method of a high-toughness polyglycolide block copolymer. The two blocks are polyglycolide polymer and aliphatic-aromatic copolyester, respectively. The prepared block polymer has good mechanical properties, with an elongation at break of 50-600% and a tensile strength of 25-100 MPa. However, the low degradation of the aliphatic-aromatic copolyester still affects the degradation performance of the copolyester.

[0004] In addition, document 1 (Synthesis, Microstructure, and Properties of High-Molar-Mass Polyglycolide Copolymers with Isolated Methyl Defects) studies the effect of different methyl side chain contents on the mechanical properties of polyglycolide copolymers. By introducing methyl glycolide and lactide to regulate the proportion of methyl side chains, the introduced comonomer is a degradable monomer, but the elongation at break of the polymer is improved by less than 10%, so the prepared polymer is still a brittle material. Document 2 (Enhanced degradation of poly(ethylene terephthalate) by the addition of lactic acid / glycolic acid: composting degradation, seawater degradation behavior and comparison of degradation mechanism) reports a PET / PGA copolyester. By a two-step polymerization process, copolyesters containing different proportions of PGA are prepared. Among them, PETG80 has a mineralization rate close to 25% under composting conditions for 120 days, and has certain degradation performance; and the tensile strength can reach 65 MPa, but the elongation at break is extremely low (<10%), which limits its more extensive application.

[0005] In summary, it is still a challenge to prepare polyglycolide-based copolymers with excellent degradation performance and balanced mechanical properties at present.

[0006] Another method to improve the toughness of PGA is to blend some flexible or elastic materials with PGA, but this process often brings the following problems:

[0007] (1) The toughening material has poor compatibility with PGA, and additional compatibilizers are needed;

[0008] Patent CN 113462138 A proposes a modified PGA degradable material, which is obtained by blending PBAT, calcium carbonate and PGA in a molten state. The prepared blended material has good elongation at break (>400%). However, due to the large difference in structure between PBAT and PGA, 5-25 parts of a compatibilizer need to be added to improve the compatibility between PBAT and PGA during the blending process. The compatibilizer used is ADR resin with an epoxy equivalent weight of 300 g / mol or more and a weight average molecular weight of 3000-5000, which increases the additional production cost and reduces the degradation performance of the blended material. Patent CN 114605800 A provides a PLA / PGA / (PBAT / ADR) alloy and a preparation method thereof. When the ratio of PLA / PGA / (PBAT / ADR) is 50 / 35 / (15 / 1.5), the yield strength of the blend is 56 MPa and the elongation at break is 237%, and the mechanical properties are excellent, but a compatibilizer still needs to be added during material preparation.

[0009] (2) The toughening material is a non-degradable material, which reduces the degradation performance of the blend;

[0010] Literature 3 (Preparation and Properties of Poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) / Polyglycolic Acid(PETG / PGA)Blends) reports a preparation method of PETG / PGA / ADR(65 / 35 / 0.3-0.9) blend material. The prepared blended material has good mechanical properties, with a tensile strength greater than 40 MPa and an elongation at break greater than 100%. However, the addition of non-degradable PETG material reduces the degradation performance of the blend; Literature 4 (Preparation and Properties of High Toughness PGA / TPEE Blends) introduces a material prepared by blending PGA with a thermoplastic elastomer and adding ADR as a blending compatibilizer. The mechanical properties of the blend are excellent, with a tensile strength greater than 50 MPa and an elongation at break exceeding 300%. However, the thermoplastic elastomer used is a PBT block elastomer, which reduces the degradation performance of the blend.

[0011] Therefore, it is of great significance to study a preparation method of degradable toughened polyester elastomer and blended polymer alloy to solve the problems in the prior art. SUMMARY

[0012] The purpose of the present application is to solve the problems in the prior art and provide a preparation method of degradable toughened polyester elastomer and blended polymer alloy.

[0013] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0014] A preparation method of a degradable toughened polyester elastomer, wherein a hydroxyl-terminated PGA (polyglycolide) oligomer and a dibasic acid are subjected to melt esterification and polycondensation to obtain the degradable toughened polyester elastomer.

[0015] The molecular weight of the hydroxyl-terminated PGA oligomer is 400-7000 g / mol.

[0016] The dibasic acid is an aliphatic linear dibasic acid or a flexible alicyclic dibasic acid with a carbon atom number of 2-12.

[0017] The present application introduces a hydroxyl-terminated PGA oligomer instead of a flexible non-degradable long chain segment, so that the final degradation product is water, carbon dioxide and a small amount of oligomers such as dimers. The hydroxyl-terminated PGA oligomer acts as a macromolecular diol, which is alternately connected in the esterification and polycondensation polymerization process with the dibasic acid to obtain an alternating copolyester. Compared with the random copolyester obtained by adding a diol and a dibasic acid for modification, the chain segments of the alternating copolymer are uniformly distributed in the polymer, so that the energy can be more uniformly dispersed in the polymer chain during the stretching process, energy dissipation is achieved, and the mechanical properties are thus regulated.

[0018] As a preferred technical scheme:

[0019] The preparation method of the degradable toughened polyester elastomer as described above, wherein the hydroxyl-terminated PGA oligomer is obtained by ring-opening polymerization of glycolide initiated by a diol, and the diol and the glycolide are mixed in a molar ratio of 1:2-60 before the ring-opening reaction.

[0020] The preparation method of the degradable toughened polyester elastomer as described above, and the specific steps are as follows:

[0021] (1) Synthesis of the hydroxyl-terminated PGA oligomer;

[0022] (1.1) The diol and the glycolide are mixed in a molar ratio of 1:2-60 and then added to a reaction kettle, and a catalyst I is added to the reaction kettle at the same time;

[0023] (1.2) First, the diol and the glycolide are fully stirred and uniformly mixed at 100-140℃ for 30-60 min, and then the temperature is raised to 160-200℃ for ring-opening polymerization reaction, and the reaction time is 3-5 hours to obtain the hydroxyl-terminated PGA oligomer;

[0024] (2) Synthesis of the degradable toughened polyester elastomer;

[0025] (2.1) The diacid is added to the reactor of step (1) according to the alcohol acid ratio of 1.1-1.6, and catalyst II is added, and the melt esterification reaction is carried out at 160-220°C until the water output rate reaches more than 90%;

[0026] (2.2) The heat stabilizer and antioxidant are added to the reactor, and the reaction temperature is raised to 210-240°C, and the melt polycondensation reaction is carried out under high vacuum conditions with a pressure of 100 Pa or less, until the stirrer current no longer continues to increase, and the product viscosity reaches the limit, that is, the reaction is considered to be completed, and the degradable toughened polyester elastomer is obtained.

[0027] The preparation method of the degradable toughened polyester elastomer as described above, in step (1.1), the dihydric alcohol is one or more of ethylene glycol, propylene glycol, 1,4-butanediol, pentanediol, hexanediol, tetramethylcyclobutanediol, 1,4-cyclohexanedimethanol, tetrahydrofurfurandimethanol, furan dimethanol, isomannitol, isoidide, isosorbide, IIDML (isoidide-2,5-dimethanol, ), IMDML (isomannide-2,5-dimethanol, ), ISDML (isosorbide-2,5-dimethanol, ), Galx-OH (2,3:4,5-di-O-Methylene-galactitol, ), Manx-OH (2,3:4,5-di-O-Methylene-D-mannitol, ), BCD (4,4'-Bicyclohexanone Glycerol Diketal, ), CHD (1,4-Cyclohexanedione Glycerol Diketal, ), CaG (Camphor quinone Diketal Glycerol, ), and CM diol (2,4:3,5-di-O-camphor-D-mannitol, ), the catalyst I is stannous chloride, stannous octoate, aluminum isopropoxide, or tin tetrachloride, and the catalyst I is added in an amount of 1-5 mol% of the dihydric alcohol.

[0028] The preparation method of the degradable toughened polyester elastomer as described above, in step (2.1), the dibasic acid is oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid or furandicarboxylic acid, which is a flexible dibasic acid, can significantly improve the toughness of the copolymer and increase the elongation at break of the copolymer; the catalyst II is one or two of tetrabutyl titanate, antimony trioxide, titanium glycolate and antimony glycolate, and the addition amount of the catalyst II is 0.1-0.3 wt% of the dibasic acid.

[0029] The preparation method of the degradable toughened polyester elastomer as described above, in step (2.2), the heat stabilizer is one or two of triphenyl phosphite, trimethyl phosphate and alkyl phosphoric acid diester, and the antioxidant is one or two of antioxidant 168, antioxidant 285 and antioxidant 1010; the addition amount of the heat stabilizer is 0.05-0.3 wt% of the dibasic acid, and the addition amount of the antioxidant is 0.05-0.3 wt% of the dibasic acid.

[0030] The preparation method of the degradable toughened polyester elastomer as described in any one of the above, the melting point of the degradable toughened polyester elastomer is 100-200℃, the intrinsic viscosity is 0.7-1.2 dL / g, the tensile strength is 10-70 MPa, and the elongation at break is 50-3600%.

[0031] The degradable toughened polyester elastomer is subjected to a degradation experiment in a neutral PBS buffer solution, and the polymer weight loss is more than 80% after degradation for 180 days at 30℃.

[0032] The application further provides a preparation method of a PGA / PGA-based elastomer blended polymer alloy, PGA and the degradable toughened polyester elastomer prepared by the method as described in any one of the above are dried (the drying temperature is 60℃, and the drying time is 12 h) and then uniformly mixed, and then subjected to blending and extrusion in a double-screw extruder to obtain the PGA / PGA-based elastomer blended polymer alloy.

[0033] As a preferred technical solution:

[0034] The preparation method of the PGA / PGA-based elastomer blended polymer alloy as described above, the blending ratio of PGA and the degradable toughened polyester elastomer is: PGA 50-90 parts, and the degradable toughened polyester elastomer 10-50 parts by weight.

[0035] The preparation method of the PGA / PGA-based elastomer blended polymer alloy as described above, the blending temperature of the double-screw extruder is 220-240℃, the blending rate is 40-60 r / min, and the blending time is 5-10 min.

[0036] The principle of the application is as follows:

[0037] The existing polyglycolide copolymerization uses non-degradable segments as copolymerization units, and although the prepared polyglycolide copolymer has good mechanical properties and elongation at break, the degradation performance of the copolymer is reduced; by introducing degradable monomers and segments, the degradation performance of the copolyester can not be destroyed, but the toughness of the copolyester is poor, and the elongation at break is at a low level.

[0038] The application adopts hydroxyl-terminated PGA oligomer and diacid esterification to prepare a rapidly degradable polyglycolide-based polyester copolyester, solves the problem of degradation performance reduction caused by the introduction of non-degradable long segments, and by adjusting the feeding ratio of dihydric alcohol and glycolide, PGA segments with different molecular weights can be prepared to adjust the crystallization performance of the PGA segments, and finally the mechanical properties of the copolymer are adjusted; at the same time, by the structure of the diacid, the copolymer has good tensile strength and elongation at break without reducing the degradation performance of the copolymer.

[0039] In the blending toughening modification experiment, there is often a problem of poor compatibility between the toughening material and the bulk material, which is due to the great difference between the molecular structures of the toughening material and the bulk material, so a compatibilizer needs to be added to promote the compatibility between the two phases. The PGA-based elastomer (degradable toughening polyester elastomer) is used to toughen PGA, and the molecular structure of the toughening material is the same as that of PGA, so it has good compatibility. The PGA-based elastomer and the PGA molecular chain are closely stacked, so that the tensile strength and elongation at break of the blended material are better than those of the traditional elastomer toughening modification process.

[0040] Advantages:

[0041] (1) The preparation method of the degradable toughening polyester elastomer can prepare hydroxyl-terminated PGA oligomers with different molecular weights by adjusting the feeding ratio of dihydric alcohol and glycolide, realize the adjustment of the mechanical strength of the polymer, and effectively improve the toughness of the copolymer by introducing flexible diacid; and no non-degradable polymer segments are added in the polymerization process, so the prepared copolyester has excellent degradation performance;

[0042] (2) The preparation method of the degradable toughening polyester elastomer can balance the tensile strength and elongation at break, the melting point is 100-200℃, the intrinsic viscosity is 0.7-1.2dL / g, the tensile strength is 10-70MPa, and the elongation at break is 50-3600%, which solves the problem that the degradation performance and mechanical properties of the existing polyglycolide copolyester cannot be balanced;

[0043] (3) The application discloses a preparation method of a blended polymer alloy, wherein a PGA-based elastomer is blended with PGA to obtain a PGA blended material, the PGA-based elastomer has the same molecular structure as the PGA, the two phases have good compatibility, no additional compatilizer is needed, the production cost is reduced, the production process is simplified, the tensile strength and elongation at break of the blended material are better than those of a traditional elastomer toughening modification process, and the degradation performance of the blended material is not affected. DETAILED DESCRIPTION

[0044] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not used to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content of the application, and these equivalent forms also fall within the scope of the appended claims of the application.

[0045] The performance indicators in the examples and comparative examples of the application involve the following test methods:

[0046] Tensile strength and elongation at break: tested according to the standard GB / T 1040.1-2018

[0047] Example 1

[0048] A preparation method of a degradable toughened polyester elastomer, the specific steps are as follows:

[0049] (1) Synthesis of hydroxyl-terminated PGA oligomer;

[0050] (1.1) Propylene glycol and glycolide are mixed according to a molar ratio of 1:30 and then added to a reaction kettle, and stannous chloride is added to the reaction kettle at the same time; the addition amount of stannous chloride is 1 mol ‰ of propylene glycol;

[0051] (1.2) First, stir at 100℃ for 45min to fully stir and uniformly mix propylene glycol and glycolide, and then heat to 160℃ for ring-opening polymerization reaction, the reaction time is 3 hours, and the obtained hydroxyl-terminated PGA oligomer has a molecular weight of 3500g / mol;

[0052] (2) Synthesis of degradable toughened polyester elastomer;

[0053] (2.1) Butanedioic acid is added to the reaction kettle in step (1) according to an alcohol-acid ratio of 1.1, and tetrabutyl titanate is added at the same time, and melt esterification reaction is carried out at 200℃ until the water yield reaches 90%; the addition amount of tetrabutyl titanate is 0.1wt% of butanedioic acid;

[0054] (2.2) Add triphenyl phosphite and antioxidant 168 to the reaction kettle, and raise the reaction temperature to 210°C. Perform melt polycondensation under high vacuum condition with a pressure of 90 Pa until the mixer current no longer continues to increase and the product viscosity reaches the limit, i.e. the reaction is considered complete, to obtain the degradable toughened polyester elastomer;

[0055] wherein the triphenyl phosphite is added in an amount of 0.05 wt% of succinic acid, and the antioxidant 168 is added in an amount of 0.05 wt% of succinic acid.

[0056] The melting point of the finally prepared degradable toughened polyester elastomer is 150°C, the intrinsic viscosity is 0.9 dL / g, the tensile strength is 60 MPa, and the elongation at break is 700%. The degradable toughened polyester elastomer is subjected to a degradation experiment in a neutral PBS buffer, and the polymer weight loss reaches 84% after 180 days of degradation at 30°C.

[0057] Example 2

[0058] A method for preparing a degradable toughened polyester elastomer, the specific steps being as follows:

[0059] (1) Synthesis of hydroxyl-terminated PGA oligomer;

[0060] (1.1) Mix 1,4-butanediol and glycolide according to a molar ratio of 1:10 and add them to a reaction kettle, and at the same time add stannous octoate to the reaction kettle; the stannous octoate is added in an amount of 1 mol‰ of 1,4-butanediol;

[0061] (1.2) First, stir at 115°C for 40 min to fully stir and uniformly mix the 1,4-butanediol and glycolide, and then raise the temperature to 160°C to perform ring-opening polymerization reaction, with a reaction time of 3 hours, to obtain a hydroxyl-terminated PGA oligomer with a molecular weight of 1200 g / mol;

[0062] (2) Synthesis of degradable toughened polyester elastomer;

[0063] (2.1) Add glutaric acid to the reaction kettle of step (1) according to an alcohol acid ratio of 1.2, and at the same time add antimony trioxide, and perform melt esterification reaction at 180°C until the water yield reaches 90%; the antimony trioxide is added in an amount of 0.1 wt% of glutaric acid;

[0064] (2.2) Add trimethyl phosphate and antioxidant 285 to the reaction kettle, and raise the reaction temperature to 220°C. Perform melt polycondensation under high vacuum condition with a pressure of 90 Pa until the mixer current no longer continues to increase and the product viscosity reaches the limit, i.e. the reaction is considered complete, to obtain the degradable toughened polyester elastomer;

[0065] The trimethyl phosphate is added in an amount of 0.05 wt% of glutaric acid, and the antioxidant 285 is added in an amount of 0.05 wt% of glutaric acid.

[0066] The melting point of the finally prepared degradable toughened polyester elastomer is 130 DEG C, the intrinsic viscosity is 0.75 dL / g, the tensile strength is 30 MPa, and the elongation at break is 300%. The degradable toughened polyester elastomer is subjected to a degradation experiment in a neutral PBS buffer solution, and after 180 days of degradation at 30 DEG C, the polymer weight loss reaches 81%.

[0067] Example 3

[0068] A preparation method of a degradable toughened polyester elastomer, and the specific steps are as follows:

[0069] (1) synthesis of hydroxyl-terminated PGA oligomer;

[0070] (1.1) tetramethylcyclobutanediol and glycolide are mixed according to a molar ratio of 1:2 and then added to a reaction kettle, and isopropyl alcohol aluminum is added to the reaction kettle at the same time; the isopropyl alcohol aluminum is added in an amount of 5 mol‰ of tetramethylcyclobutanediol;

[0071] (1.2) first stir at 130 DEG C for 60 min to fully stir and uniformly mix the tetramethylcyclobutanediol and glycolide, and then heat to 200 DEG C for ring-opening polymerization reaction, and the reaction time is 5 hours, to obtain a hydroxyl-terminated PGA oligomer with a molecular weight of 400 g / mol;

[0072] (2) synthesis of degradable toughened polyester elastomer;

[0073] (2.1) dodecanedioic acid is added to the reaction kettle of step (1) according to an alcohol acid ratio of 1.6, and titanium glycolate is added at the same time, and melt esterification reaction is carried out at 160 DEG C until the water yield reaches 90%; the titanium glycolate is added in an amount of 0.3 wt% of dodecanedioic acid;

[0074] (2.2) alkyl phosphoric acid diester and antioxidant 1010 are added to the reaction kettle, the reaction temperature is raised to 240 DEG C, and melt polycondensation reaction is carried out under high vacuum condition with a pressure of 90 Pa until the stirring machine current no longer continues to increase, and the product viscosity reaches the limit, that is, the reaction is considered to be completed, to obtain the degradable toughened polyester elastomer;

[0075] The alkyl phosphoric acid diester is added in an amount of 0.3 wt% of dodecanedioic acid, and the antioxidant 1010 is added in an amount of 0.3 wt% of dodecanedioic acid.

[0076] The melting point of the finally prepared degradable toughened polyester elastomer is 100℃, the intrinsic viscosity is 0.7dL / g, the tensile strength is 10MPa, and the elongation at break is 3600%; the degradable toughened polyester elastomer is subjected to a degradation experiment in a neutral PBS buffer solution, and the polymer weight loss reaches 83% after degradation for 180 days at 30℃.

[0077] Example 4

[0078] A preparation method of a degradable toughened polyester elastomer, the specific steps are as follows:

[0079] (1) Synthesis of hydroxyl-terminated PGA oligomer;

[0080] (1.1) A mixture of pentanediol and hexanediol with a molar ratio of 1:1 is mixed with glycolide at a molar ratio of 1:40, and then added into a reaction kettle, and tin tetrachloride is added into the reaction kettle at the same time; the addition amount of tin tetrachloride is 3mol‰ of the mixture of pentanediol and hexanediol;

[0081] (1.2) First, stir at 125℃ for 50min to make the mixture of pentanediol and hexanediol and glycolide fully stirred and uniform, and then heat to 180℃ for ring-opening polymerization reaction, the reaction time is 4 hours, and the obtained hydroxyl-terminated PGA oligomer has a molecular weight of 4700g / mol;

[0082] (2) Synthesis of degradable toughened polyester elastomer;

[0083] (2.1) Decanedioic acid is added into the reaction kettle of step (1) according to an alcohol acid ratio of 1.4, and antimony glycol is added at the same time, and melt esterification reaction is carried out at 210℃ until the water production rate reaches 90%; the addition amount of antimony glycol is 0.2wt% of decanedioic acid;

[0084] (2.2) Add triphenyl phosphite and antioxidant 168 into the reaction kettle, and increase the reaction temperature to 230℃, and carry out melt polycondensation reaction under high vacuum condition with a pressure of 90Pa, until the stirring machine current no longer continues to increase, and the product viscosity reaches the limit, that is, the reaction is considered to be completed, and the degradable toughened polyester elastomer is obtained;

[0085] The addition amount of triphenyl phosphite is 0.2wt% of decanedioic acid, and the addition amount of antioxidant 168 is 0.2wt% of decanedioic acid.

[0086] The melting point of the finally prepared degradable toughened polyester elastomer is 183℃, the intrinsic viscosity is 1dL / g, the tensile strength is 50MPa, and the elongation at break is 1200%; the degradable toughened polyester elastomer is subjected to a degradation experiment in a neutral PBS buffer solution, and the polymer weight loss reaches 83% after degradation for 180 days at 30℃.

[0087] Example 5

[0088] A method for preparing a degradable toughened polyester elastomer, the specific steps are as follows:

[0089] (1) Synthesis of hydroxyl-terminated PGA oligomer;

[0090] (1.1) A mixture of 1,4-cyclohexanedimethanol and isosorbide with a molar ratio of 1:1 is mixed with glycolide at a molar ratio of 1:60, and then added to a reaction kettle, and stannous chloride is added to the reaction kettle at the same time; the addition amount of stannous chloride is 1 mol‰ of the mixture of 1,4-cyclohexanedimethanol and isosorbide;

[0091] (1.2) First, stir at 140℃ for 30min to make the mixture of 1,4-cyclohexanedimethanol and isosorbide and glycolide fully stirred and uniform, and then heat to 160℃ for ring-opening polymerization reaction, the reaction time is 3 hours, and the hydroxyl-terminated PGA oligomer with a molecular weight of 7000g / mol is obtained;

[0092] (2) Synthesis of degradable toughened polyester elastomer;

[0093] (2.1) Azelaic acid is added to the reaction kettle of step (1) according to an alcohol acid ratio of 1.2, and a mixture of titanium glycol and antimony glycol with a mass ratio of 1:1 is added at the same time, and melt esterification reaction is carried out at 220℃ until the water production rate reaches 90%; the addition amount of the mixture of titanium glycol and antimony glycol is 0.1wt% of azelaic acid;

[0094] (2.2) A mixture of trimethyl phosphate and alkyl phosphoric acid diester with a mass ratio of 1:1 and a mixture of antioxidant 285 and antioxidant 1010 with a mass ratio of 1:1 are added to the reaction kettle, and the reaction temperature is raised to 240℃, and melt polycondensation reaction is carried out under high vacuum condition with a pressure of 90Pa until the stirring machine current no longer continues to increase, and the product viscosity reaches the limit, that is, the reaction is considered to be completed, and the degradable toughened polyester elastomer is obtained;

[0095] The addition amount of the mixture of trimethyl phosphate and alkyl phosphoric acid diester with a mass ratio of 1:1 is 0.1wt% of azelaic acid, and the addition amount of the mixture of antioxidant 285 and antioxidant 1010 with a mass ratio of 1:1 is 0.1wt% of azelaic acid.

[0096] The melting point of the finally prepared degradable toughened polyester elastomer is 200℃, the intrinsic viscosity is 1.2dL / g, the tensile strength is 70MPa, and the elongation at break is 50%; the degradable toughened polyester elastomer is subjected to degradation experiment in neutral PBS buffer solution, and the polymer weight loss reaches 82% after degradation for 180 days at 30℃.

[0097] Example 6

[0098] A PGA / PGA-based elastomer blending polymer alloy preparation method, the specific process is as follows:

[0099] After 50 parts of PGA and 50 parts of the degradable toughening polyester elastomer prepared in Example 1 are uniformly mixed after being dried at 60°C for 12h, they are extruded in a twin-screw extruder at 220°C for 10min, and the blending rate is 60r / min, to obtain a PGA / PGA-based elastomer blending polymer alloy.

[0100] The final PGA / PGA-based elastomer blending polymer alloy has a tensile strength of 65MPa and an elongation at break of 350%.

[0101] Example 7

[0102] A PGA / PGA-based elastomer blending polymer alloy preparation method, the specific process is as follows:

[0103] After 60 parts of PGA and 40 parts of the degradable toughening polyester elastomer prepared in Example 2 are uniformly mixed after being dried at 60°C for 12h, they are extruded in a twin-screw extruder at 225°C for 8min, and the blending rate is 55r / min, to obtain a PGA / PGA-based elastomer blending polymer alloy.

[0104] The final PGA / PGA-based elastomer blending polymer alloy has a tensile strength of 25MPa and an elongation at break of 250%.

[0105] Example 8

[0106] A PGA / PGA-based elastomer blending polymer alloy preparation method, the specific process is as follows:

[0107] After 70 parts of PGA and 30 parts of the degradable toughening polyester elastomer prepared in Example 3 are uniformly mixed after being dried at 60°C for 12h, they are extruded in a twin-screw extruder at 230°C for 7min, and the blending rate is 50r / min, to obtain a PGA / PGA-based elastomer blending polymer alloy.

[0108] The final PGA / PGA-based elastomer blending polymer alloy has a tensile strength of 35MPa and an elongation at break of 1400%.

[0109] Example 9

[0110] A PGA / PGA-based elastomer blending polymer alloy preparation method, the specific process is as follows:

[0111] 80 parts of PGA and 20 parts of the degradable toughened polyester elastomer prepared in Example 4 were mixed uniformly after being dried at 60℃ for 12 h, and then extruded in a twin-screw extruder at 235℃ for 6 min at a blending rate of 45 r / min to obtain a PGA / PGA-based elastomer blend polymer alloy.

[0112] The PGA / PGA-based elastomer blend polymer alloy finally obtained has a tensile strength of 64 MPa and an elongation at break of 350%.

[0113] Example 10

[0114] A PGA / PGA-based elastomer blend polymer alloy was prepared by the following method:

[0115] 90 parts of PGA and 10 parts of the degradable toughened polyester elastomer prepared in Example 5 were mixed uniformly after being dried at 60℃ for 12 h, and then extruded in a twin-screw extruder at 240℃ for 5 min at a blending rate of 40 r / min to obtain a PGA / PGA-based elastomer blend polymer alloy.

[0116] The PGA / PGA-based elastomer blend polymer alloy finally obtained has a tensile strength of 80 MPa and an elongation at break of 35%.

Claims

1. A process for the preparation of a degradable toughened polyester elastomer characterized by: The hydroxyl-terminated PGA oligomer is prepared by melt esterification and polycondensation of the hydroxyl-terminated PGA oligomer and a dibasic acid; The molecular weight of the hydroxyl-terminated PGA oligomer is 400-7000 g / mol; The hydroxyl-terminated PGA oligomer is prepared by ring-opening polymerization of glycolide using a dihydric alcohol as an initiator, wherein the dihydric alcohol and the glycolide are mixed at a molar ratio of 1:2-60 and then subjected to ring-opening reaction. The dibasic acid is oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid or furandicarboxylic acid.

2. The method for preparing a biodegradable toughened polyester elastomer according to claim 1, characterized in that, The specific steps are as follows: (1) Synthesis of the hydroxyl-terminated PGA oligomer; (1.1) The dihydric alcohol and the glycolide are mixed at a molar ratio of 1:2-60 and then added into a reaction kettle, and a catalyst I is added into the reaction kettle at the same time; (1.2) The dihydric alcohol and the glycolide are first stirred at 100-140 ℃ for 30-60 min to make them fully stirred and uniform, and then the temperature is raised to 160-200 ℃ for ring-opening polymerization reaction, and the reaction time is 3-5 hours to obtain the hydroxyl-terminated PGA oligomer; (2) Synthesis of the degradable toughened polyester elastomer; (2.1) The dibasic acid is added into the reaction kettle of step (1) at an alcohol-acid ratio of 1.1-1.6, and a catalyst II is added at the same time, and melt esterification reaction is carried out at 160-220 ℃ until the water yield reaches more than 90%; (2.2) The thermal stabilizer and the antioxidant are added into the reaction kettle, the reaction temperature is raised to 210-240 ℃, and melt polycondensation reaction is carried out under high vacuum condition at a pressure of less than 100 Pa until the stirring machine current no longer increases, and the product viscosity reaches the limit, which is regarded as the completion of the reaction, to obtain the degradable toughened polyester elastomer.

3. The method of making a degradable, toughened polyester elastomer according to claim 2, wherein, In step (1.1), the dihydric alcohol is one or more of ethylene glycol, propylene glycol, 1,4-butanediol, pentanediol, hexanediol, tetramethylcyclobutanediol, 1,4-cyclohexanedimethanol, tetrahydrofurfuryl diol, furfuryl diol, isomannide, isoidide, isosorbide, IIDML, IMDML, ISDML, Galx-OH, Manx-OH, BCD, CHD, CaG and CM diol, the catalyst I is stannous chloride, stannous octoate, aluminum isopropoxide or tin tetrachloride, and the catalyst I is added at 1-5 mol‰ of the dihydric alcohol.

4. The method for preparing a biodegradable toughened polyester elastomer according to claim 2, characterized in that, In step (2.1), the catalyst II is one or both of tetrabutyl titanate, antimony trioxide, titanium glycolate and antimony glycolate, and the catalyst II is added at 0.1-0.3 wt% of the dibasic acid.

5. The method for preparing a biodegradable toughened polyester elastomer according to claim 2, characterized in that, In step (2.2), the thermal stabilizer is one or both of triphenyl phosphite, trimethyl phosphate and alkyl phosphoric acid di-ester, the antioxidant is one or both of antioxidant 168, antioxidant 285 and antioxidant 1010, the thermal stabilizer is added at 0.05-0.3 wt% of the dibasic acid, and the antioxidant is added at 0.05-0.3 wt% of the dibasic acid.

6. The process for the preparation of a degradable toughened polyester elastomer according to any one of claims 1 to 5, characterized in that, The melting point of the degradable toughened polyester elastomer is 100-200 ℃, the intrinsic viscosity is 0.7-1.2 dL / g, the tensile strength is 10-70 MPa, and the elongation at break is 50-3600%. The degradable toughened polyester elastomer is subjected to a degradation experiment in a neutral PBS buffer solution, and is degraded for 180 days at 30 DEG C, and the weight loss of the polymer is more than 80%.

7. A process for the preparation of a PGA / PGA-based elastomeric polymer alloy, characterized by: The PGA and the degradable toughened polyester elastomer prepared by the method of any one of claims 1-6 are uniformly mixed after drying, and are then blended and extruded in a twin-screw extruder to obtain a PGA / PGA-based elastomer blended polymer alloy.

8. The process for the preparation of a PGA / PGA-based elastomeric polymer alloy according to claim 7, characterized in that, The blending ratio of the PGA and the degradable toughened polyester elastomer is as follows: 50-90 parts of PGA and 10-50 parts of the degradable toughened polyester elastomer.

9. The method for preparing a PGA / PGA-based elastomer blend polymer alloy according to claim 7, characterized in that, The blending temperature of the twin-screw extruder is 220-240 DEG C, the blending speed is 40-60 r / min, and the blending time is 5-10 min.