Reactivity ratios and thermal and dielectric studies of n-butyl methacrylate and methacrylamide copolymers

Free-radical copolymerization of n-butyl methacrylate (B) and methacrylamide (M) was carried out in the presence of 2,2'-azobisisobutyronitrile (AIBN) in dimethyl formamide (DMF) at 60°C. The percentage composition of the copolymers was established by elemental analysis. The reactivity ratios as determined by the Finemann—Ross (F—R) and the Kelen–Tudős (K—T) methods are r1 (B) = 2.75 ± 0.01, r2 (M) = 0.2 ± 0.01 and r1 = 2.70 ± 0.05, r2 = 0.19 ± 0.02, respectively. The copolymers were characterized by IR, 1H-NMR, thermal, and dielectric studies. Glass transition temperature (Tg) values were determined by DSC. Dielectric studies were carried out to understand the segmental motions and the effect of composition on dielectric loss. © 1993 John Wiley & Sons, Inc.