New Polyacetal Process from Formaldehyde Polymerization in the Presence of a Chain Transfer Agent

Abstract

Abstract A new polyacetal process from formaldehyde polymerization in the presence of a chain-transfer agent was developed. For the acetal homopolymer, highly purified formaldehyde is polymerized in the presence of acetic anhydride. Thus, an end-capped polymer can be obtained during polymerization. This concept gave us a very simple process for manufacturing the acetal homopolymer, compared to the conventional process. If trifunctional or tetrafunctional alcoholic compounds are used as chain-transfer agents, branched poly(oxymethylene) is obtained; the melt viscosity of this branched poly(oxymethylene) shows a higher pressure dependence than the linear poly(oxymethylene). If a functional polymer is used as the chain-transfer agent, which has an active hydrogen, the acetal block copolymer, which shows characteristic properties, can be obtained.