Oligomers as initiators of free radical polymerization

Methyl methacrylate, benzyl methacrylate, butyl methacrylate, and methacrylic acid can be polymerized by 1, 2, 2-tetraphenyl-1, 2-diphenoxyethane (TPPA), 1, 1, 2, 2-tetraphenyl-1, 2-bis-(trimethylsiloxy) ethane (TPSA), and 1, 1, 2, 2-tetraphenyl-1, 2-dicyanoethane (TPCA) (1–3). The polymerization with these initiators is characterized by three steps; in the first period oligomers from MMA and initiator radicals are formed by primary radical termination.