PHOTOPOLYMERIZATION OF MULTIFUNCTIONAL MONOMERS .4. ACRYLATES WITH CARBAMATE OR OXAZOLIDONE STRUCTURE

i.r. Spectroscopy was used to study the polymerization of acrylic monomers exposed as thin films to intense u.v. radiation. The polymerization rate of monoacrylate derivatives was markedly increased by the presence of a carbamate or oxazolidone group in the monomer unit. For the most reactive system, 20 msec of exposure in an inert atmosphere were sufficient to reach 80% conversion and obtain an insoluble polymer, with a quantum yield of 4.000 mol. photon-1. In the presence of an epoxy-diacrylate resin, the photopolymerization of carbamate-or oxazolidone monoacrylates was found to develop five times faster and more extensively than for diacrylic monomers. When used as reactive diluents in photopolymerizable resins, such monomers were shown to impart hardness, flexibility and impact resistance to the u.v. cured coating.