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Atom transfer radical polymerization of styrene initiated by the novel initiator N-bromosuccinimide

Abstract Heterogeneous atom transfer radical polymerization of styrene initiated by N-bromosuccinimide in bulk was successfully carried out with CuBr/2,2’-bipyridine as the catalyst. The kinetics follow first order in monomer and molecular weights (polydispersities Mw/Mn = 1.23 - 1.66) increase linearly with monomer conversion, indicating the ‘living’/controlled nature of the polymerization. However, the number-average molecular weights were usually higher than the theoretical ones. That demonstrates the relatively low efficiency of the initiator, the causes of which are discussed. The obtained polystyrenes functionalized with α-α-pyrrolidine- 2,5-dionyl and ω-Br as the end groups were characterized by 1H NMR spectroscopy. They can be used as macroinitiators for chain extension reaction. A polymerization mechanism for this novel initiation system is proposed.