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–Tüdős (K—T) methods are r 1 (B) = 2.75 ± 0.01, r 2 (M) = 0.2 ± 0.01 and r 1 = 2.70 ± 0.05, r 2 = 0.19 ± 0.02, respectively. The copolymers were characterized by IR, 1 H‐NMR, thermal, and dielectric studies. Glass transition temperature ( T g ) 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.