K. Matsuzaki et al., NEW POLYACETAL PROCESS FROM FORMALDEHYDE POLYMERIZATION IN THE PRESENCE OF A CHAIN TRANSFER AGENT, Bulletin of the Chemical Society of Japan, 67(9), 1994, pp. 2560-2566
A new polyacetal process from formaldehyde polymerization in the prese
nce of a chain-transfer agent was developed. For the acetal homopolyme
r, highly purified formaldehyde is polymerized in the presence of acet
ic anhydride. Thus, an end-capped polymer can be obtained during polym
erization. This concept gave us a very simple process for manufacturin
g the acetal homopolymer, compared to the conventional process. If tri
functional or tetrafunctional alcoholic compounds are used as chain-tr
ansfer agents, branched poly(oxymethylene) is obtained; the melt visco
sity of this branched poly(oxymethylene) shows a higher pressure depen
dence than the linear poly(oxymethylene). If a functional polymer is u
sed as the chain-transfer agent, which has an active hydrogen, the ace
tal block copolymer, which shows characteristic properties, can be obt
ained.