Copolymerization of Acrylonitrile with [(2-Methacryloyloxy)alkoxy]trimethylsilanes

Acrylonitrile (AN) was copolymerized with [(2-methacryloyloxy)-ethoxy] trimethylsilane (2-MAETMS) and [(2-methacryloyloxy)-propoxy] trimethylsilane (2-MAPTMS) in dimethylformamide (DMF) and dimethylsulfoxide (DMSO) between 50 and 70°C using azobisisobutyronitrile (AIBN) as initiator. The copolymer composition was determined by silicon estimation, and the reactivity ratios were calculated by the Kelen-Tiidbs method. Li both systems, r1 (AN) and r2(2-MAETMS/2-MAPTMS) are higher in DMF compared to the values in DMSO. Arrhenius parameters were derived for the AN-2-MAETMS system. The difference between the activation energies (E11-E12) favors self-propagation for the acrylonitrile radical, whereas A11/A12 favors cross-propagation. In the case of the 2-MAETMS radical, E22 - E21 favors cross-propagation but A22/A21 favors self-propagation. The influence of the comonomers on some of the basic properties of copolymers (e.g., intrinsic viscosity and glass transition temperature) have also been studied.