Abstract
Free-radical photopolymerization of Cyclic Allylic Sulfide monomer (CAS monomer) was investigated. Polymerization reaction was monitored by NMR and Photo-DSC in the presence or in the absence of oxygen. The reaction of CAS monomer was much less affected by oxygen than that of usual methacrylate monomer. Chain propagation spices of the CAS monomer react with oxygen to produce peroxy radical which terminates polymerization reaction. Then the peroxy radical was lead to two kinds of radical spices which originate from SH and CH2 group at α position of the sulfur atom in the terminated ring-opening CAS polymer. The reduction of oxygen inhibition occurs by a series of chain transfer and oxygen scavenging reaction
