Preparation method of degradable toughened polyester elastomer and blended polymer alloy

Abstract

The invention relates to a preparation method of a degradable toughened polyester elastomer and a blend polymer alloy. The preparation method comprises the following steps: carrying out melt esterification and polycondensation on a hydroxyl-terminated PGA oligomer and binary acid to prepare the degradable toughened polyester elastomer; the molecular weight of the hydroxyl-terminated PGA oligomer is 400 to 7000 g / mol; the binary acid is aliphatic linear binary acid or flexible alicyclic diacid with the carbon atom number of 2-12; and drying PGA and the degradable toughened polyester elastomer, uniformly mixing, and carrying out blending extrusion in a twin-screw extruder to obtain the PGA / PGA-based elastomer blended polymer alloy. The degradable toughening polyester elastomer prepared by the method disclosed by the invention takes balance between tensile strength and elongation at break into account, and solves the problem that the degradation property and mechanical property of the conventional polyglycolide copolyester cannot be achieved at the same time; the blended polymer alloy is prepared by using the PGA-based elastomer to modify the PGA, the two-phase compatibility is good, the process is simple, and meanwhile, the high tensile strength and toughness are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and relates to a preparation method of a degradable toughened polyester elastomer and a blended polymer alloy. Background Art

[0002] Plastics are widely used because of 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 waste in the environment. With the development of technology, many biodegradable materials have reached industrial scale, such as polylactic acid (PLA) and polyglycolide (PGA). However, these materials are brittle and their 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 copolyesters 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 crushed. Finally, the crushed glycolic acid copolyester is subjected to solid phase polycondensation. The glycolic acid copolymer obtained by this process has a lower melting point than PGA and has better thermal processing properties, but the preparation process is cumbersome, and the adipic acid-ethylene glycol segments generated during the polymerization process are 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, glycolic acid block copolyester material, firstly preparing furandicarboxylic acid-butanediol oligomer and glycolic acid oligomer respectively, and then co-polycondensing, the obtained copolyester has a good elongation at break (220%), but the degradation performance of furandicarboxylic acid-butanediol oligomer is poor, so that the degradation performance of the copolyester decreases. Patent CN117343293 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, elongation at break is 50-600%, and tensile strength is 25-100MPa, but the low degradation of aliphatic-aromatic copolyester still affects the degradation performance of the copolyester.

[0004] In addition, the literature 1 (Synthesis, Microstructure, and Properties of High-Molar-Mass Polyglycolide Copolymers with Isolated Methyl Defects) studied the effect of different methyl side chain contents on the mechanical properties of polyglycolide copolymers. By introducing methyl glycolide and lactide to adjust the methyl side chain ratio, the introduced comonomer is a degradable monomer, but the elongation at break of the polymer is slightly improved (<10%), so the prepared polymer is still a brittle material. Literature 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) reported a PET / PGA copolyester. Through a two-step polymerization process, copolyesters containing different proportions of PGA were prepared. Among them, the mineralization rate of PETG80 under composting conditions was close to 25% for 120 days, and it had certain degradation performance; and the tensile strength could reach 65MPa, but the elongation at break was extremely low (<10%), which limited its wider application.

[0005] In summary, the preparation of polyglycolide-based copolymers with excellent degradation performance and balanced mechanical properties still faces certain challenges.

[0006] Using some flexible or elastic materials to blend and modify PGA is another way to improve the toughness of PGA, but this process often brings the following problems:

[0007] (1) The toughening material has poor compatibility with PGA and requires additional compatibilizer;

[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%), but due to the large difference in structure between PBAT and PGA, 5 to 25 parts of a compatibilizer need to be added during the blending process to improve the compatibility between PBAT and PGA. The compatibilizer used is an ADR resin with an epoxy equivalent of more than 300 g / mol and a weight average molecular weight of 3000 to 5000, which increases additional production costs and reduces the degradation performance of the blended material. Patent CN 114605800 A provides a PLA / PGA / (PBAT / ADR) blend 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, the elongation at break is 237%, and the mechanical properties are excellent. However, a compatibilizer still needs to be added during the material preparation process.

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

[0010] Document 3 (Preparation and Properties of Poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) / Polyglycolic Acid(PETG / PGA)Blends) reports a method for preparing a PETG / PGA / ADR (65 / 35 / 0.3~0.9) blended material. The prepared blended material has good mechanical properties, a tensile strength greater than 40 MPa, and an elongation at break greater than 100%, but the addition of non-degradable PETG material reduces the degradation performance of the blend; Document 4 (Preparation and Properties of High-Toughness PGA / TPEE Blends) introduces a material prepared by blending PGA with a thermoplastic elastomer, and ADR is added as a blending compatibilizer. The blend has excellent mechanical properties, a tensile strength greater than 50 MPa, and an elongation at break exceeding 300%, but 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 a degradable toughened polyester elastomer and a blended polymer alloy to solve the problems existing in the prior art. Summary of the invention

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

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

[0014] A method for preparing a degradable toughened polyester elastomer, comprising the steps of melt esterification and polycondensation of a hydroxyl-terminated PGA (polyglycolide) oligomer and a dibasic acid to obtain the degradable toughened polyester elastomer;

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

[0016] The dibasic acid is an aliphatic linear dibasic acid or a flexible alicyclic dibasic acid having 2 to 12 carbon atoms.

[0017] The present invention introduces hydroxyl-terminated PGA oligomers instead of flexible non-degradable long chain segments, so that the final degradation products are water, carbon dioxide and a small amount of dimers and other oligomers. The hydroxyl-terminated PGA oligomers act as macromolecular diols, and are alternately connected in the esterification polycondensation polymerization process with dibasic acids to obtain alternating copolyesters. Compared with the random copolyesters obtained by traditional addition of diols and dibasic acids, the chain segments of the alternating copolymers are evenly distributed in the polymer, so that during the stretching process, energy can be more evenly dispersed in the polymer chain to achieve energy dissipation, thereby achieving the regulation of mechanical properties.

[0018] As the preferred technical solution:

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

[0020] The preparation method of the above-mentioned degradable toughened polyester elastomer comprises the following specific steps:

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

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

[0023] (1.2) First, stir at 100-140° C. for 30-60 minutes to fully mix the diol and glycolide, then heat to 160-200° C. to carry out a ring-opening polymerization reaction for 3-5 hours to obtain a hydroxyl-terminated PGA oligomer;

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

[0025] (2.1) adding the dibasic acid into the reaction kettle of step (1) at an alcohol-acid ratio of 1.1 to 1.6, and simultaneously adding the catalyst II, and performing a melt esterification reaction at 160 to 220° C. until the water yield reaches more than 90%;

[0026] (2.2) Add a heat stabilizer and an antioxidant to the reactor, raise the reaction temperature to 210-240°C, and carry out a melt polycondensation reaction under a high vacuum condition with a pressure below 100 Pa until the current of the stirrer no longer increases and the product viscosity reaches a limit. The reaction is considered to be complete, and a degradable toughened polyester elastomer is obtained.

[0027] The method for preparing a degradable toughened polyester elastomer as described above, wherein the diol in step (1.1) is ethylene glycol, propylene glycol, 1,4-butanediol, pentanediol, hexanediol, tetramethylcyclobutanediol, 1,4-cyclohexanedimethanol, tetrahydrofuran dimethanol, furan dimethanol, isomannide, isoidide, isosorbide, IIDML (isoidose-2,5-dimethanol, )、IMDML(isomannose-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, ), catalyst I is stannous chloride, stannous octoate, aluminum isopropoxide or tin tetrachloride, and the amount of catalyst I added is 1 to 5 mol‰ of the diol.

[0028] In the method for preparing a degradable toughened polyester elastomer as described above, the dibasic acid in step (2.1) 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 and can significantly improve the toughness and elongation at break of the copolymer; the catalyst II is one or two of tetrabutyl titanate, antimony trioxide, ethylene glycol titanium and ethylene glycol antimony, and the addition amount of the catalyst II is 0.1 to 0.3 wt% of the dibasic acid.

[0029] In the method for preparing a 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 phosphate diester, and the antioxidant is one or two of antioxidant 168, antioxidant 285 and antioxidant 1010; the amount of the heat stabilizer added is 0.05-0.3wt% of the dibasic acid, and the amount of the antioxidant added is 0.05-0.3wt% of the dibasic acid.

[0030] A method for preparing a degradable toughened polyester elastomer as described in any one of the above items, wherein the degradable toughened polyester elastomer has a melting point of 100-200°C, an intrinsic viscosity of 0.7-1.2 dL / g, a tensile strength of 10-70 MPa, and an elongation at break of 50-3600%;

[0031] The degradation experiment of the degradable toughened polyester elastomer was carried out in a neutral PBS buffer solution. The polymer lost more than 80% of its weight after degradation at 30°C for 180 days.

[0032] The present invention also provides a method for preparing a PGA / PGA-based elastomer blended polymer alloy, comprising drying (drying temperature is 60° C., drying time is 12 h) PGA and a degradable toughened polyester elastomer prepared by any of the above methods, mixing them evenly, and then blending and extruding them in a twin-screw extruder to obtain a PGA / PGA-based elastomer blended polymer alloy.

[0033] As the preferred technical solution:

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

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

[0036] The principle of the present invention is as follows:

[0037] The existing polyglycolide copolymer uses non-degradable chain segments as copolymer units. Although the prepared polyglycolide copolymer has good mechanical properties and elongation at break, the degradation performance of the copolymer is reduced. The introduction of degradable monomers and chain segments does not destroy the degradation performance of the copolyester, but makes the copolyester have poor toughness and a low elongation at break.

[0038] The invention adopts hydroxyl-terminated PGA oligomers and dibasic acid esters for esterification and polycondensation to prepare rapidly degradable polyglycolide-based polyester copolyester, thereby solving the problem that the degradation performance of the copolymer is reduced due to the introduction of non-degradable long chain segments. PGA segments with different molecular weights can be prepared by adjusting the feed ratio of diol to glycolide, thereby adjusting the crystallization performance of the PGA segments, and finally achieving the regulation of the mechanical properties of the copolymer. At the same time, through the structure of the dibasic acid, the copolymer can have 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 main material. This is because the molecular structure of the toughening material and the main body is quite different, so it is necessary to add a compatibilizer to promote the compatibility between the two phases. The present invention uses a PGA-based elastomer (degradable toughened polyester elastomer) to toughen PGA. The toughening material has the same molecular structure as PGA, so it has good compatibility. The PGA-based elastomer and the PGA molecular chain are stacked tightly, 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] Beneficial effects:

[0041] (1) The present invention provides a method for preparing a degradable toughened polyester elastomer. By adjusting the feed ratio of diol to glycolide, hydroxyl-terminated PGA oligomers with different molecular weights can be prepared to achieve regulation of the mechanical strength of the polymer. Then, a flexible dibasic acid is introduced to effectively improve the toughness of the copolymer. In addition, no non-degradable polymer chain segments are added during the polymerization process, and the prepared copolyester has excellent degradation performance.

[0042] (2) A method for preparing a degradable toughened polyester elastomer of the present invention. The prepared degradable toughened polyester elastomer takes into account the balance between tensile strength and elongation at break, has a melting point of 100 to 200°C, an intrinsic viscosity of 0.7 to 1.2 dL / g, a tensile strength of 10 to 70 MPa, and an elongation at break of 50 to 3600%, thus solving the problem that the prior art polyglycolide copolyester cannot have both degradation properties and mechanical properties.

[0043] (3) A method for preparing a blended polymer alloy of the present invention comprises blending a PGA-based elastomer with PGA to obtain a PGA blended material. The PGA-based elastomer and PGA have the same molecular structure and good compatibility between the two phases. No additional compatibilizer is required, which reduces production costs and simplifies the production process. While not affecting the degradation performance of the blend, the tensile strength and elongation at break of the blended material are superior to those of the traditional elastomer toughening and modification process. DETAILED DESCRIPTION

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

[0045] The test methods involved in the performance indicators in the embodiments and comparative examples of the present invention are as follows:

[0046] Tensile strength, elongation at break: tested in accordance with GB / T 1040.1-2018 standard

[0047] Example 1

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

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

[0050] (1.1) Propylene glycol and glycolide were mixed in a molar ratio of 1:30 and added to a reactor, and stannous chloride was added to the reactor at the same time; the amount of stannous chloride added was 1 mol‰ of propylene glycol;

[0051] (1.2) First, stir at 100° C. for 45 min to fully mix propylene glycol and glycolide, then heat to 160° C. to carry out a ring-opening polymerization reaction for 3 hours to obtain a hydroxyl-terminated PGA oligomer with a molecular weight of 3500 g / mol;

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

[0053] (2.1) adding succinic acid to the reaction kettle of step (1) at a ratio of 1.1 to alcohol and acid, and simultaneously adding tetrabutyl titanate, and performing a melt esterification reaction at 200° C. until the water yield reaches 90%; the amount of tetrabutyl titanate added is 0.1 wt % of the succinic acid;

[0054] (2.2) Add triphenyl phosphite and antioxidant 168 into the reactor, raise the reaction temperature to 210°C, and carry out melt polycondensation reaction under high vacuum conditions with a pressure of 90 Pa until the current of the stirrer no longer increases and the viscosity of the product reaches the limit, which means that the reaction is completed, and a degradable toughened polyester elastomer is obtained;

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

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

[0057] Example 2

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

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

[0060] (1.1) 1,4-butanediol and glycolide were mixed in a molar ratio of 1:10 and added to a reactor, and stannous octoate was added to the reactor at the same time; the amount of stannous octoate added was 1 mol‰ of 1,4-butanediol;

[0061] (1.2) First, stirring at 115° C. for 40 min to fully mix 1,4-butanediol and glycolide, and then heating to 160° C. to carry out a ring-opening polymerization reaction for 3 hours to obtain a hydroxyl-terminated PGA oligomer with a molecular weight of 1200 g / mol;

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

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

[0064] (2.2) Trimethyl phosphate and antioxidant 285 were added to the reactor, the reaction temperature was raised to 220°C, and a melt polycondensation reaction was carried out under a high vacuum condition of 90 Pa until the current of the stirrer no longer increased and the viscosity of the product reached the limit, which indicated that the reaction was completed, and a degradable toughened polyester elastomer was obtained;

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

[0066] The final prepared degradable toughened polyester elastomer has a melting point of 130°C, an intrinsic viscosity of 0.75 dL / g, a tensile strength of 30 MPa, and an elongation at break of 300%. The degradable toughened polyester elastomer was subjected to a degradation experiment in a neutral PBS buffer solution, and after degradation at 30°C for 180 days, the polymer lost 81% of its weight.

[0067] Example 3

[0068] A method for preparing a degradable toughened polyester elastomer, the specific steps are as follows:

[0069] (1) Synthesis of hydroxyl-terminated PGA oligomers;

[0070] (1.1) Tetramethylcyclobutanediol and glycolide were mixed in a molar ratio of 1:2 and added to a reactor, and aluminum isopropoxide was added to the reactor at the same time; the amount of aluminum isopropoxide added was 5 mol‰ of tetramethylcyclobutanediol;

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

[0072] (2) Synthesis of degradable toughened polyester elastomers;

[0073] (2.1) adding dodecanedioic acid to the reaction kettle of step (1) at an alcohol-acid ratio of 1.6, and adding ethylene glycol titanium at the same time, and performing a melt esterification reaction at 160° C. until the water yield reaches 90%; the amount of ethylene glycol titanium added is 0.3 wt % of the dodecanedioic acid;

[0074] (2.2) Add alkyl phosphate diester and antioxidant 1010 into the reaction kettle, raise the reaction temperature to 240°C, and carry out melt polycondensation reaction under high vacuum conditions with a pressure of 90 Pa until the current of the stirrer no longer increases and the viscosity of the product reaches the limit, which means that the reaction is completed, and a degradable toughened polyester elastomer is obtained;

[0075] The addition amount of alkyl phosphate diester is 0.3 wt % of dodecanedioic acid, and the addition amount of antioxidant 1010 is 0.3 wt % of dodecanedioic acid.

[0076] The final prepared degradable toughened polyester elastomer has a melting point of 100°C, an intrinsic viscosity of 0.7dL / g, a tensile strength of 10MPa, and an elongation at break of 3600%. The degradable toughened polyester elastomer was subjected to a degradation experiment in a neutral PBS buffer solution, and after degradation at 30°C for 180 days, the polymer lost 83% of its weight.

[0077] Example 4

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

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

[0080] (1.1) A mixture of pentanediol and hexanediol in a molar ratio of 1:1 and glycolide in a molar ratio of 1:40 were mixed and added to a reaction kettle, and tin tetrachloride was added to the reaction kettle at the same time; the amount of tin tetrachloride added was 3 mol‰ of the mixture of pentanediol and hexanediol;

[0081] (1.2) First, the mixture was stirred at 125° C. for 50 min to fully mix the pentanediol and hexanediol mixture with glycolide, and then the temperature was raised to 180° C. to carry out a ring-opening polymerization reaction for 4 hours to obtain a hydroxyl-terminated PGA oligomer with a molecular weight of 4700 g / mol;

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

[0083] (2.1) adding sebacic acid to the reaction kettle of step (1) at an alcohol-acid ratio of 1.4, and adding ethylene glycol antimony at the same time, and performing a melt esterification reaction at 210° C. until the water yield reaches 90%; the amount of ethylene glycol antimony added is 0.2 wt % of the sebacic acid;

[0084] (2.2) Add triphenyl phosphite and antioxidant 168 into the reactor, raise the reaction temperature to 230°C, and carry out melt polycondensation reaction under high vacuum conditions with a pressure of 90 Pa until the current of the stirrer no longer increases and the viscosity of the product reaches the limit, which means that the reaction is completed, and a degradable toughened polyester elastomer is obtained;

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

[0086] The final prepared degradable toughened polyester elastomer has a melting point of 183°C, an intrinsic viscosity of 1dL / g, a tensile strength of 50MPa, and an elongation at break of 1200%. The degradable toughened polyester elastomer was subjected to a degradation experiment in a neutral PBS buffer solution, and after degradation at 30°C for 180 days, the polymer lost 83% of its weight.

[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 oligomers;

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

[0091] (1.2) First, stirring at 140° C. for 30 min to fully mix the mixture of 1,4-cyclohexanedimethanol and isosorbide with glycolide, and then heating to 160° C. to carry out a ring-opening polymerization reaction for 3 hours to obtain a hydroxyl-terminated PGA oligomer with a molecular weight of 7000 g / mol;

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

[0093] (2.1) adding azelaic acid to the reaction kettle of step (1) at an alcohol-acid ratio of 1.2, and simultaneously adding a mixture of ethylene glycol titanium and ethylene glycol antimony in a mass ratio of 1:1, and performing a melt esterification reaction at 220° C. until the water yield reaches 90%; the amount of the ethylene glycol titanium and ethylene glycol antimony mixture added is 0.1 wt % of the azelaic acid;

[0094] (2.2) A mixture of trimethyl phosphate and alkyl phosphate diester in a mass ratio of 1:1 and a mixture of antioxidant 285 and antioxidant 1010 in a mass ratio of 1:1 were added to a reactor, the reaction temperature was raised to 240°C, and a melt polycondensation reaction was carried out under a high vacuum condition of a pressure of 90 Pa until the current of the stirrer no longer increased and the viscosity of the product reached a limit, which indicated that the reaction was completed, and a degradable toughened polyester elastomer was obtained;

[0095] Among them, the added amount of the mixture of trimethyl phosphate and alkyl phosphate diester in a mass ratio of 1:1 is 0.1wt% of azelaic acid, and the added amount of the mixture of antioxidant 285 and antioxidant 1010 in a mass ratio of 1:1 is 0.1wt% of azelaic acid.

[0096] The final prepared degradable toughened polyester elastomer has a melting point of 200°C, an intrinsic viscosity of 1.2 dL / g, a tensile strength of 70 MPa, and an elongation at break of 50%. The degradable toughened polyester elastomer was subjected to a degradation experiment in a neutral PBS buffer solution, and after degradation at 30°C for 180 days, the polymer lost 82% of its weight.

[0097] Example 6

[0098] A method for preparing a PGA / PGA-based elastomer blended polymer alloy, the specific process is as follows:

[0099] By weight, 50 parts of PGA and 50 parts of the degradable toughened polyester elastomer prepared in Example 1 were dried at 60°C for 12 hours and then mixed evenly, then blended and extruded in a twin-screw extruder at 220°C for 10 minutes at a blending rate of 60 r / min to obtain a PGA / PGA-based elastomer blended polymer alloy.

[0100] The tensile strength of the PGA / PGA-based elastomer blended polymer alloy finally prepared is 65 MPa, and the elongation at break is 350%.

[0101] Example 7

[0102] A method for preparing a PGA / PGA-based elastomer blended polymer alloy, the specific process is as follows:

[0103] By weight, 60 parts of PGA and 40 parts of the degradable toughened polyester elastomer prepared in Example 2 were dried at 60°C for 12 hours and then mixed evenly, then blended and extruded in a twin-screw extruder at 225°C for 8 minutes at a blending rate of 55 r / min to obtain a PGA / PGA-based elastomer blended polymer alloy.

[0104] The tensile strength of the PGA / PGA-based elastomer blended polymer alloy finally prepared is 25 MPa, and the elongation at break is 250%.

[0105] Example 8

[0106] A method for preparing a PGA / PGA-based elastomer blended polymer alloy, the specific process is as follows:

[0107] By weight, 70 parts of PGA and 30 parts of the degradable toughened polyester elastomer prepared in Example 3 were dried at 60°C for 12 hours and mixed evenly, then blended and extruded in a twin-screw extruder at 230°C for 7 minutes at a blending rate of 50 r / min to obtain a PGA / PGA-based elastomer blended polymer alloy.

[0108] The tensile strength of the PGA / PGA-based elastomer blended polymer alloy finally prepared is 35 MPa, and the elongation at break is 1400%.

[0109] Example 9

[0110] A method for preparing a PGA / PGA-based elastomer blended polymer alloy, the specific process is as follows:

[0111] By weight, 80 parts of PGA and 20 parts of the degradable toughened polyester elastomer prepared in Example 4 were dried at 60°C for 12 hours and mixed evenly, then blended and extruded in a twin-screw extruder at 235°C for 6 minutes at a blending rate of 45 r / min to obtain a PGA / PGA-based elastomer blended polymer alloy.

[0112] The tensile strength of the PGA / PGA-based elastomer blended polymer alloy finally prepared is 64 MPa, and the elongation at break is 350%.

[0113] Example 10

[0114] A method for preparing a PGA / PGA-based elastomer blended polymer alloy, the specific process is as follows:

[0115] By weight, 90 parts of PGA and 10 parts of the degradable toughened polyester elastomer prepared in Example 5 were dried at 60°C for 12 hours and then mixed evenly, then blended and extruded in a twin-screw extruder at 240°C for 5 minutes at a blending rate of 40 r / min to obtain a PGA / PGA-based elastomer blended polymer alloy.

[0116] The tensile strength of the PGA / PGA-based elastomer blended polymer alloy finally prepared is 80 MPa and the elongation at break is 35%.

Claims

1. A method for preparing a degradable toughened polyester elastomer, characterized in that: The hydroxyl-terminated PGA oligomer and dibasic acid are melt-esterified and polycondensed to obtain a degradable toughened polyester elastomer; The molecular weight of the hydroxyl-terminated PGA oligomer is 400 to 7000 g / mol; The dibasic acid is an aliphatic linear dibasic acid or a flexible alicyclic dibasic acid having 2 to 12 carbon atoms.

2. The method for preparing a degradable toughened polyester elastomer according to claim 1, characterized in that: The hydroxyl-terminated PGA oligomer is obtained by using a diol-initiated glycolide ring-opening polymerization method, wherein the diol and glycolide are mixed in a molar ratio of 1:2 to 60 and then subjected to a ring-opening reaction.

3. The method for preparing a degradable toughened polyester elastomer according to claim 1 or 2, characterized in that: The specific steps are as follows: (1) Synthesis of hydroxyl-terminated PGA oligomers; (1.1) diol and glycolide are mixed in a molar ratio of 1:2 to 60 and added to a reaction kettle, and catalyst I is added to the reaction kettle at the same time; (1.2) First, stir at 100-140° C. for 30-60 minutes to fully mix the diol and glycolide, then heat to 160-200° C. to carry out a ring-opening polymerization reaction for 3-5 hours to obtain a hydroxyl-terminated PGA oligomer; (2) Synthesis of degradable toughened polyester elastomers; (2.1) adding the dibasic acid into the reaction kettle of step (1) at an alcohol-acid ratio of 1.1 to 1.6, and adding catalyst II at the same time, and performing a melt esterification reaction at 160 to 220° C. until the water yield reaches more than 90%; (2.2) Add a heat stabilizer and an antioxidant to the reactor, raise the reaction temperature to 210-240°C, and carry out a melt polycondensation reaction under a high vacuum condition with a pressure below 100 Pa until the current of the stirrer no longer increases and the product viscosity reaches a limit. The reaction is considered to be complete, and a degradable toughened polyester elastomer is obtained.

4. The method for preparing a degradable toughened polyester elastomer according to claim 3, characterized in that: In step (1.1), the diol is one or more of ethylene glycol, propylene glycol, 1,4-butanediol, pentanediol, hexanediol, tetramethylcyclobutanediol, 1,4-cyclohexanedimethanol, tetrahydrofuran dimethanol, furan dimethanol, isomannide, isoidide, isosorbide, IIDML, IMDML, ISDML, Galx-OH, Manx-OH, BCD, CHD, CaG and CM diol, and catalyst I is stannous chloride, stannous octoate, aluminum isopropoxide or tin tetrachloride, and the amount of catalyst I added is 1 to 5 mol‰ of the diol.

5. The method for preparing a degradable toughened polyester elastomer according to claim 3, characterized in that: 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, and the catalyst II is one or two of tetrabutyl titanate, antimony trioxide, titanium glycol and antimony glycol, and the added amount of catalyst II is 0.1 to 0.3 wt% of the dibasic acid.

6. The method for preparing a degradable toughened polyester elastomer according to claim 3, characterized in that: In step (2.2), the heat stabilizer is one or two of triphenyl phosphite, trimethyl phosphate and alkyl phosphate diester, and the antioxidant is one or two of antioxidant 168, antioxidant 285 and antioxidant 1010; the addition amount of the heat stabilizer is 0.05-0.3wt% of the dibasic acid, and the addition amount of the antioxidant is 0.05-0.3wt% of the dibasic acid.

7. The method for preparing a degradable toughened polyester elastomer according to any one of claims 1 to 6, characterized in that: The melting point of the degradable toughened polyester elastomer is 100-200°C, the intrinsic viscosity is 0.7-1.2dL / g, the tensile strength is 10-70MPa, and the elongation at break is 50-3600%. The degradation experiment of the degradable toughened polyester elastomer was carried out in a neutral PBS buffer solution. The polymer lost more than 80% of its weight after degradation at 30°C for 180 days.

8. A method for preparing a PGA / PGA-based elastomer blend polymer alloy, characterized in that: PGA and the degradable toughened polyester elastomer prepared by the method according to any one of claims 1 to 7 are dried and mixed evenly, and then blended and extruded in a twin-screw extruder to obtain a PGA / PGA-based elastomer blended polymer alloy.

9. The method for preparing a PGA / PGA-based elastomer blended polymer alloy according to claim 8, characterized in that: In terms of weight, the blending ratio of PGA and the degradable toughened polyester elastomer is: 50-90 parts of PGA and 10-50 parts of the degradable toughened polyester elastomer.

10. The method for preparing a PGA / PGA-based elastomer blended polymer alloy according to claim 8, characterized in that: The blending temperature of the twin-screw extruder is 220-240° C., the blending rate is 40-60 r / min, and the blending time is 5-10 min.