Synthesis method for stereoregularity polyester and bi-metallic catalyst

Abstract

The invention relates to a synthesis method for stereoregularity polyester and a bi-metallic catalyst. The catalyst is a bi-nuclear metal complex formed by connecting two metal centers through a biphenyl or dinaphthalene framework. The catalyst can efficiently catalyze a cyclic anhydride and internal compensation epoxyalkane polymerization reaction under the mild condition and low catalyst concentration to prepare polyester under the effect of a nucleophilic co-catalyst, the catalysis efficiency is 103-106 g of a polymer per mole of the catalyst, the molecular weight of the polymer can be adjusted within the range of 103-105, the molecular weight distribution is smaller than 2, stereoregularity can be adjusted within the range of 60-100%, the alternative structure exceeds 98%, and polyester can be degraded into a small molecular compound under a certain condition. A chiral ligand catalytic system is used, the product selectivity and alternative structure selectivity of the polymer are both higher than 98%, the excess value of enantiomer of diol obtained after degradation is higher than 70%, and wide prospects are provided for industrial application.

Description

technical field [0001] The present invention relates to a synthetic method of stereoregular polyester and its catalyst, in particular to a method for alternately copolymerizing mesoalkylene oxide and cyclic acid anhydride to form stereoregular polyester, and to catalyze the polymerization reaction bimetallic catalysts. Background technique [0002] Disposable plastic packaging and plastic daily necessities not only consume a lot of petroleum resources in production, but also are difficult to recycle and reuse after use, and are also difficult to be degraded by the environment, causing environmental pollution. Therefore, creating completely biodegradable materials and related products is one of the important research goals of the scientific community all over the world. Among them, aliphatic polyesters have attracted extensive attention due to their good biocompatibility, biodegradability, and easy processability. Currently commercialized polyester products include polyethy...

AI Technical Summary

Problems solved by technology

[0006] Most of the previously reported methods for preparing polyesters from the copolymerization of alkylene oxides and cyclic anhydrides have low catalyst activity, long reaction time, and harsh reaction conditions; few involve polyester stereochemistry, let alone direct synthesis from achiral substrates. conformational polyester

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