{HEAD ~ at least one photoinitiator} which promotes {TAIL ~ free radical polymerization} by generating reactive specie by way of unimolecular homolysis resulting from photoexcitation, said photoinitiator having the formula ##STR27## wherein A1 and A2 are the same or different and each is a benzenoid or nonbenzenoid aromatic radical 
{ HEAD ~ at least one photoinitiator } which promotes { TAIL ~ free radical polymerization } by generating reactive specie by way of unimolecular homolysis resulting from photoexcitation , said photoinitiator having the formula # # STR27 # # wherein A1 and A2 are the same or different and each is a benzenoid or nonbenzenoid aromatic radical
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH