In this paper

the effects of temperature from 60 ℃ to 80 ℃ and the molar ratios in monomer feed on the copolymerization of

α

-methylstyrene (AMS) and styrene (St) were studied. The resulting copolymers

designated as PAS

were characterized by FTIR

GPC

NMR and TGA. When the reaction temperature was below 75 ℃

the molecular weights increased almost linearly as the evolution of the copolymerization. The phenomenon revealed that AMS could mediate the conventional free radical polymerization having some features of a controlled system. As the AMS/St = 50/50 (molar) in feed

the overall fraction of the AMS unit incorporated into the copolymer was as high as 42 mol%

the monomer conversion could be more than 90 wt% and the molecular weights could reach as high as 4400. However

since the styrene is more reactive than AMS

the AMS fraction in copolymer increased with the overall monomer conversion. The

13

C-NMR revealed the products were random copolymers which had triads

such as -AMS-AMS-AMS-

-St-AMS-AMS- (-AMS-AMS-St-) and -St-AMS-St-. TGA curves demonstrated that the degradation temperature of the resulting copolymers went down from about 356.9 ℃ (0 mol% AMS) to 250.2 ℃ (42 mol% AMS). This behavior demonstrated that there exist weak bonds in the AMS-containing sequences which could be used as potential free radical generators.