A preparation method of polycaprolactone, a biodegradable polymer material for medicine

Abstract

The invention relates to a preparation method of medical biodegradable high-polymer material polycaprolactone. According to the method, an organometal compound is taken as a catalyst, polycaprolactoneis prepared with a bulk polymerization method, the production process is simple, conditions required for a reaction are lower, the reaction speed is high, the reaction time is short, the product chromaticity is good, and the molecular weight can be regulated as required; and an organometal compound catalysis system is an efficient catalysis system, the reaction time is short, the weight-average molecular weight of a product can be adjusted, the smallest molecular weight dispersion index can be 1.40, and polycaprolactone is high in catalysis activity and basically non-toxic.

Description

technical field [0001] The invention relates to a preparation method of polycaprolactone, a biodegradable polymer material used in medicine, and belongs to the technical field of medicine preparation. Background technique [0002] Since the 1960s, polycaprolactone (PCL polycaprolactone) has attracted widespread attention due to its good biocompatibility, biodegradability and memory, and its related research has also developed rapidly. PCL is a semi-crystalline polymer with a melting point of 59-64°C and a glass transition temperature of -60°C. It is rubbery at room temperature, which makes it possible to have better drug permeability than other polyesters, and can be used for implant materials in the body and sustained-release capsules of drugs. The molecular chain of PCL is relatively regular, flexible, and easy to crystallize, so it has better hydrophobicity than polyglycolide and polylactide, and it degrades slowly in the body, so it is one of the ideal implant materials...

AI Technical Summary

Problems solved by technology

Metals in common metal compound catalysts include magnesium, calcium, tin, aluminum, zinc, iron, titanium, etc.; however, in existing metal complex catalysts, the selection of ligands and metals is very important for the ring-opening polymerization. The speed and the performance of the resulting product are very critical. In the case of the same metal, the replacement and selection of the ligand often show unexpected catalytic effects. In the case of the same ligand, the replacement of the metal will also produce different results. Catalytic effect

[0005] In addition to the above-mentioned metal compound coordination catalyst systems, there are organoaluminum compound coordination catalysts and rare earth compound catalysts. The organoaluminum compound coordination catalysts mainly include alkyl aluminum, alkoxy aluminum, porphyrin aluminum and their derivatives. Among them, aluminum isopropoxide is the most effective catalyst, the reaction conditions are mild, and the molecular weight of the obtained polymer is high, but the reaction time is long, the product yield is low, the molecular weight distribution is wide, and the organoaluminum compound has certain toxicity, which limits its application in the market. Biomedical Applications

[0006] Rare earth catalysts such as halide rare earth compounds, rare earth alkoxy compounds and rare earth aryl oxide compounds can also catalyze the ring-opening polymerization of caprolactone, and its mechanism is similar to the catalytic mechanism of alkoxy aluminum (belonging to the coordination-insertion mechanism), However, the catalyst is unstable and easily hydrolyzed in the air, and the synthesis steps are too complicated