FREE-RADICAL COPOLYMERIZATION OF ALLYLOXYPHENYLSILOXANES WITH SOME VINYL MONOMERS

Two p-allyloxyphenyldisiloxane compounds, (p-allyloxyphenyl)-1,1,3,3,3 -pentamethyldisiloxane (mono-APDS) and is(p-allyloxyphenyl)-1,1,3,3-te tramethyldisiloxane (bis-APDS), were synthesized to study their radica l copolymerizations with some vinyl monomers (styrene, methyl methacry late, N-phenylmaleimide and maleic anhydride). The reactivities of all yl groups in mono-APDS and bis-APDS were found to be almost the same i n styrene and methyl methacrylate copolymerization, as evidenced by th eir composition curves, and increase with the electron-accepting abili ty of comonomers. In the case of electron-poor monomers, such as N-phe nylmaleimide and maleic anhydride, the second allyl group of bis-APDS readily took part in the crosslinking. Differential scanning calorimet ry 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.