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Development of a new advanced process for manufacturing polyacetal resins. Part III. End‐capping during polymerization for manufacturing acetal homopolymer and copolymer
Author(s) -
Masamoto J.,
Matsuzaki K.,
Iwaisako T.,
Yoshida K.,
Kagawa K.,
Nagahara H.
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070500803
Subject(s) - trioxane , copolymer , polymerization , acetal , polymer chemistry , acetic anhydride , materials science , polymer , chain transfer , chemistry , organic chemistry , radical polymerization , catalysis , composite material
Conventionally, acetal homopolymer or copolymer is obtained by the polymerization of formaldehyde or trioxane, following the end‐capping using acetic anhydride or unzipping of the unstable polymer end fraction. First, Asahi Chemical developed a new process to obtain an end‐capped polymer during polymerization of highly purified formaldehyde using acetic anhydride as the chain‐transfer agent. Use of highly purified formaldehyde and endcapping during polymerization using acetic anhydride as a chain‐transfer agent or an endcapping agent will provide a simple process for manufacturing acetal homopolymer. The polymerization mechanism was confirmed by infrared spectroscopy analysis and proton NMR analysis of the polymer obtained. Second, for the acetal copolymer, purified trioxane was copolymerized with ethylene oxide in the presence of methylal, which gave an endcapped polymer with high thermal stability. Two new intermediates from the initiation reaction of the copolymerization, 1,3,5,7‐tetraoxacyclononane (TOCN) and 1,3,5,7,10‐pentaoxacyclododecane (POCD), were isolated and a new initiation mechanism was proposed. © 1993 John Wiley & Sons, Inc.