KETENE ACETAL MONOMERS - CATIONIC PHOTOPOLYMERIZATION

A study of the photoinduced cationic polymerization of a novel series of cyclic and acyclic ketene acetal monomers was carried out. It was o bserved that the cyclic monomers underwent facile cationic polymerizat ion to give high molecular weight polymers while the acyclic ketene ac etals did not. Thermally induced polymerization was also observed on s tanding catalyzed by glass surfaces. Photoinduced cationic polymerizat ions employing both diaryliodonium and triarylsulfonium salt photoinit iators were studied. It was observed that the position and type of sub stitutents in the cyclic ketene acetals was the major factor in determ ining the proportion of vinyl and ring-opening polymerizations that ta ke place. (C) 1996 John Wiley & Sons, Inc.