The RAFT homopolymerization of St and copolymerization of St with Nsubstituted maleimides such as HPM
CPPM and BPPM
using AIBN as initiator
1-phenylethyl dithiobenzoate or cumyl dithiobenzoate as the chain transfer agent was investigated.The polymers were characterized by UV-Vis and GPC.The results suggested that both the homopolymerization and copolymerization exhibited a living behavior
and the molecular weight increased with the conversion and a narrow molecular weight distribution was achieved.For the homopolymerization
due to the unfavorable bimolecular termination of the PSt radicals
the capping efficiency of the PSt chains decreased gradually with the conversion.For the copolymerization
the charge transfer complex formation not only enhanced the reaction rate but also led to alternating sequence.The P(St-alt-BPPM) was also used as the macroinitiator for the ATRP of St to prepare comb-shaped PSt.The results implied that when NMP was used as solvent
the process proceeded in an uncontrolled fashion; on the other hand