The effects of SnC1, on the radical polymerization of N-allyl-N-phenylmethacrylamide (APM) and N-allyl-N-phenylacrylamide (APA) were investigated. The polymerizations of APM and APA with dimethyl 2,2-azobisisobutyrate (MAIB) were carried out a t 50Β°C in benzene at various concentrations (0-1.0 mol/L) of SnC1,. The polymerization rates showed a maximum on varying the S n C 4 concentration, while the molecular weights of the resulting poly(APM) and poly(APA) were decreased with increasing SnC1, concentration. In both systems, the degree of cyclization of polymers were decreased with the SnC1, concentration.
From the IR results, the cyclic structure of the resulting poly(APM)s was confirmed to be five-membered, whereas poly(APA)s contained not only five-membered but also six-membered rings. The 'H-NMR examination on the interactions of APM and APA with SnC1, revealed that these monomers form 1:l and 2:l complexes with SnC1, with fairly large stability constants. Copolymerizations of APM (Ml) with methyl methacrylate (MMA) and styrene (St) (M,) were investigated at 60Β°C in benzene in the absence of SnC1,. APM units were found to be incorporated exclusively as five-membered rings in the resulting copolymer. Monomer reactivity ratios were estimated to be rl = 0.29, r, = 4.88 for APM/ MMA and rl = 0.66, r2 = 5.39 for APM/St. The presence of equimolar (to APM) SnCl, was found to enhance the reactivity of APM towardpoly(MMA) radical; rl = 0.24, r, = 2.56.