J. Mateo, P. Bosch, F. Catalina
Dec 1, 1991
Citations
0
Influential Citations
10
Citations
Journal
Journal of Polymer Science Part A
Abstract
The behavior of the nonconjugated aminated benzophenones—4-[2′-N,N-(diethylamino)ethoxy]benzophenone (E4), 2-[2′-N,N-(diethylamino)ethoxy]-4-methoxybenzophenone (E2), and 4-N,N-dimethylaminomethylbenzophenone (DM)—as photoinitiators of MMA polymerization has been studied and the results compared with those obtained with the conjugated aminobenzophenone 4-N,N-dimethylamino-4′-isopropyl-benzophenone (CU—MI). Photoreduction behavior of these compounds in various solvents in the presence and absence of MMA has been also examined. The order of the polymerization reaction with respect to monomer and initiator concentrations has been investigated; values of initiation quantum yield (Φi), Kp/K1/2t and efficiencies of the different radicals have also been determined. Similar polymerization rates (Rp) of methyl methacrylate (MMA) were found when E4 and CU-MI were used as photoinitiators under the same range of absorbed irradiation intensity. This fact results from a compensation between the higher rate of E4 radical production (n-π* transition type) and the greater reactivity of the radicals generated from CU-MI.