Photopolymerization of the N,N-dialkylaminoethyl methacrylate-benzophenone system

In order to search for photoradical polymerization systems that are not subject to oxygen inhibition, photoradical polymerization of the N,N-dialkylaminoethyl methacrylate—aryl ketone system has been studied. It was found that photoradical polymerization of this system, where N,N-dialkylaminoethyl methacrylate functions both as a co-initiator and as a monomer, is accelerated in the presence of oxygen. The polymerization rate was faster with N,N-diethylaminoethyl methacrylate than with the N,N-dimethyl analogue. Crosslinking occurred rapidly in the presence of a multifunctional acrylate monomer, resulting in the formation of gels. As compared with photopolymerizations of acrylate monomers using non-polymerizable, low-molecular-weight alkylamine-aryl ketone combinations as photo-initiators, the present system has an advantage that less low-molecular-weight amine remains in the exposed area because it polymerizes.