Method for Preparing High Molecular Weight Polybutylene Succinate

Abstract

A method for preparing high molecular weight polybutylene succinate includes: (a) using maleic anhydride (MAH) and C1-C4 alcohols to produce dialkyl maleates and water, in which dialkyl fumarate is calculated as dialkyl maleate of an equivalent mole. A reactive distillation process is used for the purification and obtains dialkyl maleates; (b) selective hydrogenation of those dialkyl maleates in the presence of high pressure hydrogen to produce the corresponding dialkyl succinates; (c) condensation of dialkyl succinates with mostly 1,4-butanediol (BDO) and other aliphatic diols to produce high molecular weight polybutylene succinates by adding catalysts. Compared with the existing technologies, the present procedure uses a new source of raw bulk feedstocks, and circumvents or overcomes problems associated with the acidic monomer's corrosiveness, excessive formation of by-products, low yields of desired products and the relatively low molecular weight of the polybutylene succinate produced by existing technologies.

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