SUBSTITUTED VINYL BROMIDES AS PHOTOINITIATORS FOR CATIONIC POLYMERIZATIONS

The cationic polymerization of typical monomers, e.g. of oxiranes such as cyclohexene oxide and 1,4-butanedioldiglycidyl ether or of vinyl ethers such as n-butylvinyl ether, is induced by UV irradiation of monomer formulations containing a substituted vinyl bromide as light absorbing agent and an appropriate non-absorbing onium salt. Experiments performed with 1,2,2-triphenyl vinyl bromide or 1,2,2-tri(4-methoxyphenyl) vinyl bromide and N-ethoxy-2-methyl-pyridinium or triphenyl, sulfonium hexafluorophosphate are described in the paper.