Preparation of living mono‐ and dicationically growing polyacetals and attempts to prepare block copolymers thereof
作者:
Wiesława Chwiałkowska,
Przemysław Kubisa,
Stanisław Penczek,
期刊:
Die Makromolekulare Chemie
(WILEY Available online 1982)
卷期:
Volume 183,
issue 4
页码: 753-769
ISSN:0025-116X
年代: 1982
DOI:10.1002/macp.1982.021830401
出版商: Hüthig&Wepf Verlag
数据来源: WILEY
摘要:
AbstractMono‐ and dicationically living poly(1,3‐dioxolane) (pdxn) and poly (1,3‐dioxepane) (pdxp) were obtained with CF3SO3H (trifilic acid‐tfac) and (CF3SO2)2O (triflic anhydride‐tfan), respectively. Concentration of the active species and living character of polymers were established by applying the ion‐trapping technique. Addition of a second cyclic acetal to the living bifunctional polyacetal (e. g. addition of dxn to pdxp) leads to the formation of a block copolymer (according to13C NMR), but before the second monomer polymerizes completely, the transacetalization process leads to the conversion of the internal homoblock to a more or less (depending on time) statictical copolymer. Thus, competition of the homopropagation and transacetalization is not in favor of formation of the block copolymers with pure homoblocks, at least when the second block, built on the already existing homoblock, is formed slower than the homoblock is reshuffled by transac
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