SYNTHESIS AND POLYMERIZATION OF 1-METHYL-4-DIPHENYL-1-(P-VINYLPHENYL)-1-SILACYCLOPENT-3-ENE

A monomer having a silacyclopentene ring, 4-diphenyl-1-(p-vinylphenyl) -1-silacyclopent-3-ene (VPSiCP), was synthesized by a coupling reactio n of 2,3-diphenyl-1,3-butadiene-magnesium complex with p-vinylphenylme thyldichlorosilane. The VPSiCP was obtained in a high yield of 80.1% a s white needles (mp, ca. 103 degrees C) by recrystallization from acet one. The initial rate of homopolymerization of VPSiCP in benzene was f ound to be ca. 21 times higher than that of styrene in spite of its hi ghly bulky substituent. The radical copolymerization of VPSiCP (MI) wi th styrene (St) or methyl methacrylate (MMA) were carried out in benze ne by AIBN at 60 degrees C. Monomer reactivity ratios in the copolymer izations with the comonomers (M-2) were determined by Kelen-Tudos meth od: r(1)=0.67+/-0.06, r(2)=0.65+/-0.05 for St; r(1)=0.85, r(2)=0.47 fo r MMA. Q and e values were also calculated by Alfrey-Price equation; Q =0.74, e=0.11 for St comonomer; Q=1.08, e=-056 for MMA comonomer.