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Polymerization chemistry of the family of cyclic imino ethers
Author(s) -
Saegusa Takeo,
Aoi Keigo,
Miyamoto Masatoshi,
Chujo Yoshiki
Publication year - 1991
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19910470114
Subject(s) - chemistry , polymerization , cationic polymerization , isomerization , polymer chemistry , ionic polymerization , ring opening polymerization , chain growth polymerization , substituent , monomer , organic chemistry , radical polymerization , polymer , catalysis
Characteristics of the polymerization mechanisms of the family of cyclic imino ethers are described. The variety of the mechanism of propagation has been systematized on the basis of the nature of propagating species, i.e., cationic or electrophilic covalent (dipole) species. In the polymerizations of 2‐alkyl cyclic imino ethers (5‐ and 6‐membered), propagation mechanism via one of these two different species has been established, which is dependent upon the relative nucleophilic reactivities of the monomer and the counter anion derived from initiator. The polymerization of cyclic pseudoureas having a cyclic amine substituent at 2‐position proceeds in two different ways. Ionic propagation leads to the single isomerization/ring‐opening polymerization involving only the cyclic imino ether ring. On the other hand, covalent propagation gives rise to the double isomerization ring‐opening polymerization involving the two rings of cyclic imino ether and cyclic amine. Polymerization of 5‐membered cyclic iminocarbonate with a sulfonate initiator proceeds through the isomerization/ring‐opening of 2‐oxazoline ring. The same monomer was isomerized to the corresponding cyclic urethane when it was treated with benzyl bromide.