Cyclopolymerization. Part XXXII radical polymerization of α-(2-phenylallyloxy)methylstyrene: synthesis of highly cyclized polymers with high glass transition temperatures and thermal stability

A new 1,6-diene, α-(2-phenylallyloxy)methylstyrene (1), was synthesized and its radical cyclopolymerizations were studied, since 1 is expected to yield highly cyclized polymers with thermal stability and high glass transition temperatures. A low homopolymerization tendency of the monofunctional counterpart of 1 can be assumed reasonably, because it is a derivative of α-methylstyrene with a low ceiling temperature. This means that intermolecular propagation leading to pendant unsaturations is hard to occur during the polymerization of 1, which results in the formation of highly cyclized polymers. In fact, the degree of cyclization of poly(1) obtained at 180 °C attained the value 99%. Structural studies using a monomeric cyclic compound obtained by the telomerization of 1 permitted to assign main repeating cyclic units of poly(1) to a six-membered ring. The poly(1)s with a higher degree of cyclization were found to be stable up to 300 °C on thermogravimetric analyses and their glass transition temperatures were detected at temperatures over 250 °C.