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Facile synthesis and characterization of star‐shaped polystyrene: self‐condensing atom transfer radical copolymerization of N ‐[4‐(α‐bromoisobutyryloxy)phenyl]maleimide and styrene
Author(s) -
Cao Yun,
Hong Yan,
Zhai Guangqun,
Zhang Dongliang,
Song Yan,
Yu Qiang,
Ren Qiang,
Jiang Bibiao
Publication year - 2008
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2446
Subject(s) - atom transfer radical polymerization , branching (polymer chemistry) , maleimide , polystyrene , polymer chemistry , copolymer , styrene , materials science , differential scanning calorimetry , glass transition , melt flow index , radical polymerization , polymer , polymerization , composite material , thermodynamics , physics
BACKGROUND: Generation of stars around in situ formed cores provides a facile approach to star‐shaped polymers. Therefore the self‐condensing atom transfer radical copolymerization (SCATRCP) of N ‐[4‐(α‐bromoisobutyryloxy)phenyl]maleimide (BiBPM) and a large excess of styrene (St) was investigated. RESULTS: BiBPM and St formed a charge transfer complex (CTC), which underwent the SCATRCP, leading to the branched core initiating the atom transfer radical polymerization of St, finally giving star‐shaped polystyrene (PS). Kinetic and structural study showed that a higher dosage of BiBPM resulted in an enhanced polymerization rate, a higher degree of branching and a larger number of short PS arms. Differential scanning calorimetry suggested that the glass transition temperature of the star‐shaped PS decreased with molecular weight. Melt rheometry showed that even a slightly branched architecture of the PS led to a significantly lower viscosity; both the melt flow index and the activation energy increased with the degree of branching. CONCLUSION: Due to the preferential consumption of BiBPM and formation of a CTC, even a very low dosage of BiBPM could lead to star‐shaped PS, which, in comparison with linear analogues, could possess much better melt fluidity. Copyright © 2008 Society of Chemical Industry