Premium
Copolyethers with controlled structure: Mechanism of formation and microstructure
Author(s) -
Bednarek Melania,
Kubisa Przemyslaw
Publication year - 1998
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19981320132
Subject(s) - copolymer , tetrahydrofuran , polymer chemistry , cationic polymerization , monomer , mole fraction , ether , microstructure , materials science , reaction mechanism , chemistry , organic chemistry , polymer , catalysis , solvent , metallurgy
Cationic copolymerization of 3‐membered cyclic ethers (oxiranes) with 5‐membered cyclic ether (tetrahydrofuran) leads to linear copolyethers containing significant amount of cyclic fraction. When the copolymerization is conducted in the presence of diols, telechelic copolymers are formed by the process in which oxirane is incorporated into copolymer irreversibly by Activated Monomer mechanism, while tetrahydrofuran is incorporated reversibly by Active Chain End mechanism. Thus both kinetic and thermodynamic factors can be used to control the rate of the incorporation of comonomers. Studies of the kinetics of the competing reactions leading to formation of copolymer, studies of copolymer microstructure by 13 C‐NMR and analysis of the composition of the cyclic fraction, led to the correlation between the copolymer microstructure and the amount of cyclic fraction formed. The dependence of the cyclic fraction content on the reaction conditions was therefore explained.