Method for preparing biomedical polyether/polyester block copolymer

Abstract

The invention belongs to the technical field of biological materials and particularly relates to a method for preparing a biomedical polyether / polyester block copolymer. In the method, the polyether / polyester block copolymer is prepared by triggering lactone to perform ring-opening polymerization under the vacuum condition by using fully dried polyether. The method comprises the following steps of: adding polyether, the lactone and a catalyst into a polymerization bottle; and heating and vacuumizing the polymerization bottle to remove moisture and solvent remained in a polymerization system to prepare the polyether / polyester block copolymer. The method is simple and practicable, the reaction conditions are easy to control, and a series of copolymers with different molecular weights can be obtained only by controlling the feed ratio of the polyether to the lactone; the reaction time can be shortened by a polymerization process so as to avoid side reaction, and the obtained copolymer has a stable structure, and high uniformity of molecular weight; and the content of the unreacted monomer and a heavy metal catalyst is extremely low, and the requirements of biomedical materials can be met.

Description

technical field [0001] The invention belongs to the technical field of biological materials, and relates to a preparation method of a polyether and polyester block copolymer, in particular to a preparation method of a biomedical polyether / polyester block copolymer. Background technique [0002] In recent years, nanotechnology-based drug delivery methods have attracted great attention from researchers. Among them, the nanomicellar carrier system formed by self-assembly of amphiphilic block copolymers in aqueous solution has become a new type of drug carrier with great application prospects. At present, there is a lot of evidence that polymer nanomicelles have unique advantages compared with other drug carriers: resistance to dilution, stable structure in blood; long circulation characteristics; small particle size of micelles Leaky vascular areas (such as tumor sites) have stronger penetration capacity and have more opportunities to accumulate at the target site; the targeti...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: in the process of adding lactone and catalyst, the reaction system is inevitably in contact with the outside world, and it is very easy to bring in moisture in the air, and the lactone is very easy to hydrolyze in the molten state

However, this method has the following obvious disadvantages: firstly, the polymerization activity of lactic acid is low, and a large amount of lactic acid remains in the final product, and it is necessary to remove the remaining lactic acid monomer through repeated dissolution-precipitation. Low, and the stability between batches of products is poor, and the harmful heavy metal catalysts cannot be effectively removed in the repeated precipitation process

In addition, due to the high temperature of polycondensation and the long reaction time, the product is easy to oxidize and turn yellow.

Therefore, the above method is generally not suitable for the preparation of biomedical copolymer materials.