Premium
Preparation and kinetic analysis of PS‐ b ‐PBA block copolymer by 4‐oxo‐TEMPO capped polystyrene macroinitiators
Author(s) -
Kuo KuoHuai,
Chiu WenYen,
Cheng KuoChung
Publication year - 2009
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.30227
Subject(s) - copolymer , polymer chemistry , polystyrene , dispersity , polymerization , materials science , radical polymerization , hydroxylamine , polymer , chemistry , organic chemistry , composite material
Polystyrene‐block‐poly( n ‐butyl acrylate) block copolymers were prepared from 4‐oxo‐2,2,6,6‐tetramethylpiperidinooxy (4‐oxo‐TEMPO) capped polystyrene macroinitiators at a high temperature, 165°C. It was found that the number‐average molecular weight of PBA chains in block copolymers could reach above 10,000 rapidly at early stage of polymerization with a narrow polydispersity index of 1.2–1.4, but after that, the polymerization seemed to be retarded. Furthermore, according to the kinetic analysis, the concentration of 4‐oxo‐TEMPO was increased mainly by the hydrogen transfer reaction of hydroxylamine (4‐oxo‐TEMPOH) to growing radicals during polymerization. This increase in 4‐oxo‐TEMPO concentration could retard the growth of polymer chains. The rate constant of the hydrogen transfer reaction of 4‐oxo‐TEMPOH to growing radicals, k H , estimated by the kinetic model is about 9.33 × 10 4 M ‐1 s −1 at 165°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009