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Synthesis of arborescent (Dendritic) polystyrenes via controlled inimer-type reversible addition-fragmentation chain transfer polymerization Part A Polymer chemistry

Author:
Heidenreich, Andrew J., Puskas, Judit E.
Source:
Journal of polymer science 2008 v.46 no.23 pp. 7621-7627
ISSN:
0887-624X
Subject:
molecular weight, nuclear magnetic resonance spectroscopy, polymerization, polystyrenes, styrene
Abstract:
The reversible addition-fragmentation chain transfer (RAFT) copolymerization of styrene and 4-vinylbenzyl dithiobenzoate, a RAFT-based inimer (initiator-monomer), is described. Controlled polymerization was achieved in bulk conditions using thermal initiation at 110 °C to give arborescent polystyrene (arbPSt). The number-average molecular weights of the polymers increased linearly with conversion and were much higher than theoretically calculated for a linear polymerization, reaching Mn = 364,000 g/mol with Mw/Mn = 2.65. Branching analysis by NMR showed an average of 3.5 branches per chain. SEC data, which were similar to those measured in arborescent polyisobutylene, supported the architectural analysis.
Agid:
2112605