阅读说明：本技术 一种生物降解热塑性聚酯弹性材料及其制备方法 (Biodegradable thermoplastic polyester elastic material and preparation method thereof ) 是由 贾亚听 何创龙 隋晓锋 于 2020-06-28 设计创作，主要内容包括：本发明涉及一种生物降解热塑性聚酯弹性材料及其制备方法。该方法包括：将癸二酸与聚乙二醇混合,搅拌,真空条件下酯化反应,加入催化剂,真空条件下预缩合反应,将得到的预聚物继续反应,纯化。该方法采用的反应单体比较简单,无毒无刺激,生物安全性好,在生物医学中应用广泛,所得到的材料具有良好的生物相容性和生物降解性。(The invention relates to a biodegradable thermoplastic polyester elastic material and a preparation method thereof. The method comprises the following steps: mixing sebacic acid and polyethylene glycol, stirring, carrying out esterification reaction under a vacuum condition, adding a catalyst, carrying out pre-condensation reaction under the vacuum condition, continuously reacting the obtained prepolymer, and purifying. The reaction monomer adopted by the method is simple, non-toxic and non-irritant, has good biological safety, is widely applied in biomedicine, and the obtained material has good biocompatibility and biodegradability.)

1. A biodegradable thermoplastic polyester elastic material is prepared from sebacic acid and polyethanediol through fusion polycondensation in the presence of catalyst, reaction between hydroxy and carboxyl, dewatering, condensation polymerization and purifying.

2. The material of claim 1, wherein the polyester elastomer is a high molecular weight linear poly (sebacic acid-polyethylene glycol) ester having the formula:

3. The material as claimed in claim 1, wherein the molecular weight of the polyethylene glycol is 100-400 g-mol^-1(ii) a The catalyst is one of stannous octoate, stannous chloride, stannous octoate/p-toluenesulfonic acid and stannous chloride/p-toluenesulfonic acid.

4. A method for preparing a biodegradable thermoplastic polyester elastic material comprises the following steps:

mixing sebacic acid and polyethylene glycol in a molar ratio of 0.99:1-1.10:1, stirring, carrying out esterification reaction under a vacuum condition, adding a catalyst, carrying out pre-condensation reaction under the vacuum condition, continuously reacting the obtained prepolymer, and purifying to obtain the biodegradable thermoplastic polyester elastic material.

5. The method of claim 4, wherein the agitating is: stirring the mixture at the temperature of 160 ℃ under the protection of nitrogen until the sebacic acid is completely dissolved.

6. The method according to claim 4, wherein the esterification reaction has the following process parameters: the reaction temperature is 120 ℃ and 180 ℃, the pressure is 0.1-4000Pa, and the reaction time is 0.5-8 hours.

7. The method according to claim 4, wherein the catalyst is one of stannous octoate, stannous chloride, stannous octoate/p-toluenesulfonic acid and stannous chloride/p-toluenesulfonic acid, the molar amount of the p-toluenesulfonic acid is equal to that of the stannous octoate or the stannous chloride, and the molar amount of the stannous octoate or the stannous chloride is 0.0005-0.02 times of that of hydroxyl or carboxyl in the reaction system.

8. The method according to claim 4, wherein the pre-condensation reaction has the following process parameters: the reaction temperature is 120-180 ℃, the pressure is 0.1-3000Pa, and the reaction time is 2-20 hours.

9. The method of claim 4, wherein the process parameters of the continuous reaction are: the reaction temperature is 180 ℃ and 280 ℃, the pressure is lower than 3000Pa, and the reaction time is 1-20 hours.

10. Use of a polyester elastomer material according to claim 1.

Technical Field

The invention belongs to the field of biodegradable high polymer materials and preparation thereof, and particularly relates to a biodegradable thermoplastic polyester elastic material and a preparation method thereof.

Background

The biodegradable high molecular material has important significance in biomedicine and has wide application in the fields of tissue engineering, drug release, biosensing and the like. Biodegradable polyesters are the most common class of biodegradable polymeric materials, and include both thermoplastic and thermoset types. Thermoplastic biodegradable polyesters such as polylactic acid, polyglycolic acid, polycaprolactone and copolymers thereof, have good processability and higher mechanical strength, have been successfully applied in the fields of surgical sutures, internal fixation of fractures, tissue engineering, drug sustained release and the like, but are not suitable for soft tissue engineering because of high crystallinity, high modulus, poor elasticity and slow degradation. Poly-sebacic acid glycerol ester, poly-citric acid polyethylene glycol ester and derivative polymers thereof are a plurality of thermosetting biodegradable polyester materials which are researched more, have good elasticity and degradability, are more suitable for being applied to soft tissue engineering such as cardiac muscle, blood vessel, nerve conduit and the like, but have harsh preparation conditions, need to be solidified, are not dissolved in any solvent after being crosslinked, can not be subjected to secondary melting processing, and are greatly limited in practical application. Thermoplastic elastomers are a more specific class of polymeric materials and are characterized by combining the processability of thermoplastic materials with the high elasticity of thermoset materials, making them both plastic and highly elastic. At present, the reports on thermoplastic elastomers in biodegradable high molecular materials are less, and the development of biodegradable thermoplastic elastomer materials is of great significance for promoting the solution of many problems in the biomedical field.

Sebacic acid and polyethylene glycol are two common reaction monomers used for preparing biodegradable high polymer materials, and various biodegradable materials prepared by directly taking sebacic acid and polyethylene glycol as raw materials are reported. For example, polyethylene glycol is dicarboxylated and then reacts with sebacic acid to obtain poly (sebacic acid-polyethylene glycol) anhydride (chemical reagent, 2007,29(3): 161-163); polysebacic anhydride reacts with polyethylene glycol to obtain polysebacic anhydride-polyethylene glycol block copolymer (ion exchange and adsorption, 2008,24(3): 246-253); or the PEG-SA polyester (Polymer,2006,47:3760-3766) is obtained by the solution polymerization of sebacoyl chloride and polyethylene glycol. The materials mainly utilize the high hydrophilicity of polyethylene glycol to improve the hydrophilicity of polyanhydride materials, or form a hydrophilic-hydrophobic block copolymer to form hydrogel with certain water absorption and retention functions, and the adopted polyethylene glycol has higher molecular weight (Mn is more than or equal to 400). The material is mainly used as a functional material for constructing a drug controlled release carrier or hydrogel, cannot be used as a structural material, and does not have the performance of a thermoplastic elastomer.

Disclosure of Invention

The invention aims to solve the technical problem of providing a biodegradable thermoplastic polyester elastic material and a preparation method thereof so as to fill the blank in the prior art.

The invention provides a biodegradable thermoplastic polyester elastic material, which is prepared by carrying out melt polycondensation on sebacic acid and polyethylene glycol under a catalyst, reacting hydroxyl and carboxyl among molecules, dehydrating, condensing, polymerizing and purifying.

The polyester elastic material is high molecular weight linear poly (sebacic acid-polyethylene glycol) ester, and the structural formula of the poly (sebacic acid-polyethylene glycol) ester is as follows:

wherein n is more than or equal to 50, and m is 2-8.

The number average molecular weight (Mn) of the polyester elastic material can reach 13 multiplied by 10⁴g·mol^-1Above, the polydispersity index (Mw/Mn) is between 1.2 and 4.

The molecular weight of the polyethylene glycol is 100-400g & mol^-1。

The catalyst is one of stannous octoate, stannous chloride, stannous octoate/p-toluenesulfonic acid and stannous chloride/p-toluenesulfonic acid.

The polymerization reaction temperature is 120-280 ℃, the pressure is lower than 3325Pa, and the reaction time is 4-50 hours.

The invention also provides a preparation method of the biodegradable thermoplastic polyester elastic material, which comprises the following steps:

mixing sebacic acid and polyethylene glycol in a molar ratio of 0.99:1-1.10:1, stirring, carrying out esterification reaction under a vacuum condition, adding a catalyst, carrying out pre-condensation reaction under the vacuum condition, continuously reacting the obtained prepolymer, and purifying to obtain the biodegradable thermoplastic polyester elastic material.

The stirring is as follows: stirring the mixture at the temperature of 160 ℃ under the protection of nitrogen until the sebacic acid is completely dissolved.

The technological parameters of the esterification reaction are as follows: the reaction temperature is 120 ℃ and 180 ℃, the pressure is 0.1-4000Pa, and the reaction time is 0.5-8 hours.

The catalyst is any one or more of catalysts capable of catalyzing polyester polymerization; preferably a tin-based catalyst; more preferably, the molar amount of the p-toluenesulfonic acid is equal to that of the stannous octoate or the stannous chloride, and the molar amount of the stannous octoate or the stannous chloride is 0.0005 to 0.02 times (preferably 0.001 to 0.02 times) that of the hydroxyl group or the carboxyl group in the reaction system.

The technological parameters of the pre-condensation reaction are as follows: the reaction temperature is 120-180 ℃, the pressure is 0.1-3000Pa, and the reaction time is 2-20 hours.

The technological parameters of the continuous reaction are as follows: the reaction temperature is 180 ℃ and 280 ℃, the pressure is lower than 3000Pa, and the reaction time is 1-20 hours.

The purification method comprises the following steps: dissolving a polyester primary product in a good solvent, stirring to dissolve the polyester to obtain a polymer solution, and then dropping the polymer solution into a poor solvent to generate a precipitate, namely a purified product; this purification step may be performed multiple times; the good solvent and the poor solvent may be arbitrarily combined.

The good solvent is any one of tetrahydrofuran, acetone, trichloromethane, dichloromethane, N-dimethylformamide, dimethyl sulfoxide, 1, 4-dioxane and hexafluoroisopropanol.

The poor solvent is any one of water, methanol, ethanol, ether and petroleum ether.

The mass volume ratio of the polyester primary product to the good solvent is 5-30%, and the volume ratio of the good solvent to the poor solvent is 1:2-1: 10.

The purification times are 1-5 times.

The invention also provides application of the biodegradable thermoplastic polyester elastic material.

The polymerization reaction of the invention is direct melt polycondensation of sebacic acid and polyethylene glycol, and the reaction system contains no other components except monomers and catalysts. The product obtained after the synthesis reaction is an initial product, the molecular weight distribution of the product is wide, and the product with higher relative molecular weight can be obtained through a certain purification step.

The molecular chain of the biodegradable thermoplastic polyester elastic material is linear, and the material can be dissolved in various organic solvents, such as tetrahydrofuran, acetone, trichloromethane, dichloromethane, dimethyl sulfoxide, N-dimethylformamide, 1, 4-dioxane, hexafluoroisopropanol and the like, and is insoluble in water, methanol, ethanol, diethyl ether and the like. The material is in a semi-crystalline solid state at normal temperature, the glass transition temperature of the material is lower than 0 ℃, the material is in a high-elastic state at normal temperature, the elastic modulus is 0.01-2MPa, and the elongation at break is more than 1700%. The polyester material has good solubility, processability, mechanical strength, high elasticity, biocompatibility, biodegradability and thermoplasticity.

Advantageous effects

(1) The reaction monomer adopted by the invention is simple, non-toxic and non-irritant, has good biological safety, can be widely applied in biomedicine, and the obtained material has good biocompatibility and biodegradability.

(2) The thermoplastic polyester elastic material has good solubility, processability and high elasticity, and the elastic modulus of the thermoplastic polyester elastic material is matched with human soft tissues, so that the thermoplastic polyester elastic material can meet the requirements of various biomedical applications.

Drawings

FIG. 1 is a graph of the infrared spectrum of the material obtained in example 1;

FIG. 2 shows the NMR spectrum of the material obtained in example 1 (¹H-NMR) chart;

FIG. 3 is a uniaxial tensile stress-strain plot of the material obtained in example 1;

FIG. 4 is a graph of cyclic tensile stress-strain for the material obtained in example 1;

FIG. 5 is a graph of uniaxial tensile stress-strain curves for the material obtained in example 1 and the material obtained in comparative example 1.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.