PHOTOPOLYMERIZATION OF GLYCIDYL ACRYLATE AND GLYCIDYL METHACRYLATE INVESTIGATED BY DIFFERENTIAL PHOTOCALORIMETRY AND FT-IR

The kinetics of photopolymerization of glycidyl acrylate (GA) and glyc idyl methacrylate (GMA) sensitized by radical and cationic initiators have been studied using a combination of photodifferential scanning ca lorimetry (PDSC) and Fourier Transform i.r. spectroscopy (FT-i.r.). PD SC analysis shows that GA has much higher reactivity than GMA when a t ypical radical photoinitiator, 2,2-dimethoxy-2-phenylacetophenone (DMP A), was used. No great difference in rate constants and activation ene rgies between the two monomers, except the higher conversion of GA, wa s found for the cationic polymerization initiated by sulphonium salts. The results of FT-i.r. show that both double bond and epoxy ring are polymerized at the same time. For both radical and cationic initiating systems, photopolymerization kinetics are also studied as a function of initiator concentration.