Reactivities of N‐alkylitaconimides in radical copolymerizations with styrene or methyl methacrylate

Abstract

AbstractThe radical copolymerizations of N‐alkylitaconimide (RII, R = CH3, C2H5, n‐C3H7, i‐C3H7, n‐C4H9, i‐C4H9, CH2CH2Cl, CH2C6H5) (M1) with styrene (ST) (M2) or methyl methacrylate (MMA)‐(M2) were carried out at 60°C, using azobisisobutyronitrile as an initiator in tetrahydrofuran in order to clarify the substituent effect on the copolymerizations. The monomer reactivity ratios r1, r2 and the Q1 and e1 values were determined from the results obtained. It was found that the relative reactivities 1/r2 of RII toward an attack by a poloystyryl radical could be correlated not by the steric‐substituent constant Es of the alkyl group in RII but by the polar‐substituent constant σ* in Taft's equation: log(1/r2) = ρ*σ* + δ Es. According to the above equation, the ρ* and δ values were obtained as 0.55 and 0, respectively, in the RII‐ST system, while in the RII‐MMA system, the ρ* and δ values were obtained as 0.49 and 0, respectively. It was also observed that the Q1values for RII were proportional to σ* constants and that the e1 values for RII were independent of σ* substituent constant. It was also found that the weight‐average molecular weights of the copolymers are between 8.5 × 104 and 32.5 × 104.