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Synthesis of Well‐Defined Hybrid Macromonomers of Poly(ethylene oxide) and Their Reactivity in Photoinitiated Polymerization
Author(s) -
Du Juan,
Murakami Yoshitaka,
Senyo Takamichi,
Ito Koichi,
Yagci Yusuf
Publication year - 2004
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200400061
Subject(s) - cationic polymerization , chemistry , polymer chemistry , ethylene oxide , benzophenone , ethylene glycol , polymerization , vinyl ether , sulfonium , anionic addition polymerization , reactivity (psychology) , radical polymerization , organic chemistry , salt (chemistry) , copolymer , polymer , medicine , alternative medicine , pathology
Summary: α , ω ‐Hybrid (hetero‐telechelic) poly(ethylene oxide) (PEO) macromonomers carrying both cationic and radical or anionic polymerizable vinyl end groups were newly synthesized by the living anionic polymerization of ethylene oxide (EO) initiated with partially K‐alkoxidated vinylic alcohols such as the monovinyl ether of tetramethylene glycol or di(ethylene glycol) and p ‐vinylbenzyl alcohol (VBA), followed by reaction with methacryloyl chloride (MAC). They possess a couple of α ‐ and ω ‐end groups that can polymerize concurrently or selectively by radical and/or cationic or anionic mechanism. The reactivity of the radical and cationic species formed upon photolysis of benzophenone and triphenylsulfonium tetrafluoroborate towards these end groups were studied by means of 1 H NMR analysis following the disappearance of the respective olefinic groups. Studies with macromomonomers and model compounds revealed that photoexcited benzophenone abstracts hydrogen atoms from the PEO backbone to form radicals without added hydrogen donors. In the case of the sulfonium salt, both radical and cationic species are formed, which react with the respective functional groups. It was also shown that vinyl ether moieties react more readily than the methacrylate in both radical and cationic processes.The general synthetic strategy followed for the preparation of the hybrid PEO macromonomers studied here.