FREE-RADICAL COPOLYMERIZATION OF ALLYLOXYPHENYLSILOXANES WITH SOME VINYL MONOMERS

Two p-allyloxyphenyldisiloxane compounds, 1-(p-allyloxyphenyl)-1,1,3,3,3-pentamethyldisiloxane (mono-APDS) and 1,3-bis(p-allyloxyphenyl)-1,1,3,3-tetramethyldisiloxane (bis-APDS), were synthesized to study their radical copolymerizations with some vinyl monomers (styrene, methyl methacrylate, N-phenylmaleimide and maleic anhydride). The reactivities of allyl groups in mono-APDS and bis-APDS were found to be almost the same in styrene and methyl methacrylate copolymerization, as evidenced by their composition curves, and increase with the electron-accepting ability of comonomers. In the case of electron-poor monomers, such as N-phenylmaleimide and maleic anhydride, the second allyl group of bis-APDS readily took part in the crosslinking. Differential scanning calorimetry and thermogravimetry revealed that the increase of APDS contents in those copolymers led to lower glass transition temperature (T(g)) and higher thermal degradation temperature.