Preparing method for glycolic acid-hydracrylic acid random copolymer

Abstract

The invention provides a preparing method for a glycolic acid-hydracrylic acid random copolymer. The preparing method includes the steps of raw material pretreatment, pre-polycondensation and polycondensation, wherein the step of raw material pretreatment includes the substeps that a glycolic acid water solution and a hydracrylic acid water solution are treated with ultrasonic waves and filtered; the step of pre-polycondensation includes the substep that the pretreated mixed solution is subjected to pre-polycondensation at low temperature and low pressure to obtain a pre-polycondensation intermediate product; the step of polycondensation includes the substep that butyl titanate and triphenyl phosphate are added into the pre-polycondensation intermediate product for polycondensation. By means of the improved raw material components and the optimized preparing technology, the prepared glycolic acid-hydracrylic acid random copolymer has stable quality, and is large in polymerization conversion rate, large in molecular weight, high in intrinsic viscosity and particularly suitable for manufacturing medical biodegradable macromolecular structure devices such as a biodegradable medical ligation clamp and a gastrointestinal tract anastomat .

Description

technical field [0001] The invention relates to a preparation method of a biodegradable polymer material, in particular to a method for preparing a glycolic acid-hydroxypropionic acid random copolymer through direct condensation polymerization of glycolic acid-hydroxypropionic acid. Background technique [0002] In the random copolymer of glycolic acid-hydroxypropionic acid, monomeric glycolic acid and monomeric hydroxypropionic acid are randomly arranged on the macromolecular chain, and the two monomers are randomly distributed on the main chain, which destroys the symmetry and regularity of the chain properties, so that good degradation performance can be obtained. Glycolic acid-hydroxypropionic acid random copolymer is a biomedical and environmentally friendly polymer with good biocompatibility and biodegradability. Due to its unique properties, it is used in biomedical and biodegradable materials field is getting more and more attention. [0003] The preparation method...

AI Technical Summary

Problems solved by technology

The biggest advantage of the direct condensation polymerization method is that the production cost is low, and the disadvantage is that the molecular weight of the generated polymer is small, and it is difficult to obtain a polymer with high intrinsic viscosity.

The study found that the main reason why it is difficult to obtain high-viscosity polymers by direct condensation polymerization is that the purity of monomers is not enough. The aqueous solution of glycolic acid and hydroxypropionic acid used as copolymerization raw materials contains a small amount of other organic acids. The ratio of condensation polymerization to functional groups The requirements are very high. In order to obtain a polymer with high system viscosity, the carboxyl group and the hydroxyl group must be equal

For equal molar amounts of glycolic acid and hydroxypropionic acid, the number of functional groups of hydroxyl and carboxyl groups is equal, but there are other miscellaneous acids in the aqueous solution of glycolic acid and hydroxypropionic acid, resulting in high carboxyl groups, so that it is impossible to obtain a high system viscosity polymer

Secondly, the decomposition temperature of the glycolic acid-hydroxypropionic acid random copolymer is very close to the melting temperature. In the later stage of polymerization, the growth of molecular chains will be accompanied by the exchange of macromolecular chains, chain breaks and high-temperature oxidative degradation (mentioned earlier. And the "Medical Biomaterials-Polylactide PGLA (90 / 10) Research" also records that there is a situation in which the residual lactide monomer is decomposed during the polymerization process), which leads to the conversion rate of the direct condensation polymerization method If it is too low, the residual monomer defects are large, and the product quality stability of polymer products is poor