A kind of linear comb fluorescent polylactic acid and its preparation method

Abstract

A linear comb-like fluorescent polylactic acid and its preparation method belong to the technical field of polymer materials, and its structure is: the main chain is a linear macromolecular initiator residue, the side chain is polylactic acid, and the end of the side chain is a fluorescent functional group; The number average molecular weight of the linear comb fluorescent polylactic acid is 1×10 4 -50×10 4 g / mol, the number average molecular weight per arm is 0.1×10 4 -2×10 4 g / mol; the linear macromolecular initiator is a linear hydroxylated polymer, the number of hydroxyl groups of the linear macromolecular initiator is 8‑60, and the number average molecular weight is 0.1×10 4 -2×10 4 g / mol; the fluorescent functional group is a small fluorescent molecule containing a carboxyl group, and the capping rate of the small fluorescent molecule is 10%‑100%. First, a linear hydroxylated polymer initiator was synthesized by an active anion reaction, and an organic base was used as a catalyst to catalyze the ring-opening polymerization of lactide to synthesize a kind of linear comb-like polylactic acid and a fluorescent functional group for grafting reaction to prepare a linear comb highly branched fluorescent polylactic acid. The functionalization method is simple, the synthesis reaction conditions are mild, and the linear comb-like highly branched structure effectively improves the performance of the polymer and the fluorescence developing efficiency.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and relates to a class of linear comb-shaped fluorescent polylactic acid and a preparation method thereof. Background technique [0002] Aliphatic polyester is renewable, biodegradable, biocompatible and absorbable, and is an environmentally friendly green polymer material, which has a wide range of applications in the field of biomedicine, especially as a controlled release of drugs. drug delivery carrier. Due to the complexity and diversity of polymer structures, polymer materials can be endowed with more superior properties by changing the structure and composition of polymers to expand their application range. The development trend of polymer structure is from linear structure to branched structure. Most of the currently synthesized biodegradable aliphatic polyesters have linear, linear, dendritic and hyperbranched structures, and most of them have disadvantages such as low molecu...

AI Technical Summary

Problems solved by technology

[0003] At present, the low reactivity and biological activity of the most commonly used polylactic acid (PLA) material itself limits its further application in biological response, tracking, and regulation of degradation and release. Therefore, functional modification and chemical Modification has become one of the most important research directions in the field of biomedical materials

Commonly used functional modification methods include monomer modification and post-functionalization of the main chain. The process is relatively complicated, the reaction conditions are harsh, and the controllability is poor. Therefore, the functional modification of the initiator and the end modification become crucial. important