Study On Thermal Initiation In Stable Free Radical Polymerization Of Styrene

A novel radical initiator bis(4-bromomethylbenzoyl)peroxide [(BrCH₂)2BPO] having active groups for ATRP, 1-bromomethylbenzene, was synthesized. The polystyrene was prepared in bulk with (BrCH₂)2BPO as initiator in the presence of 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-l-oxyl (TEMPO-OH). The polymerization was carried out at first for 3.5h at 95℃, and then increasing temperature to 125℃. Four kinds of polystyrenes were prepared through changing [(BrCH₂)₂BPO]: [TEMPO-OH] to be 1: 1,1: 2,1: 3, 1: 4. Using polystyrene obtained above as macroinitiator, bulk atom transfer radical polymerization of styrene was carried out at 80℃. The GPC curves of the polystyrenes obtained in ATRP show double peaks .These results imply that the polymerization occurred not only by the presence of (BrCH₂)2BPO but also by thermal initiation. The polymer chains generated by (BrCH₂)2BPO having 1-bromomethylbenzene at their heads...