Kinetics of photopolymerization of acrylates with functionality of 1-6

The photopolymerization of a number of neat acrylate monomers with acrylate functionality from 1-6 was studied with photoDSC (DSC differential scanning calorimetry) and with a cure monitor using a fluorescent probe. PhotoDSC results show that conversion of monomers ranges from 40 to 100%, depending upon the functionality and structure of a monomer. Kinetics of a heat flow was well described as an autoaccelearted reaction for all monomers. Kinetics of the hardening of a sample under light at an ambient temperature was nicely fit into the two-exponential law; rate constants k(1) and k(2) in this empirical analysis were in the range of 0.5-35 min(-1). The effect of an inhibitor and of air oxygen on kinetics of photopolymerization was also studied. The dependence of the rate of polymerization and conversion upon the functionality of a monomer is discussed.