Synthesis, characterization and kinetic study of photocrosslinkable prepolymer: 2-hydroxy-3-[p-(1-{p-[2-hydroxy-3-(vinylcarbonyloxy)propoxy]phenol}-1-phenylethyl)phenoxy]propyl acrylate

Abstract

New photocrosslinkable prepolymer, 2-hydroxy-3-[p-(1-{p-[2-hydroxy-3-(vinylcarbonyloxy)propoxy]phenol}-1-phenylethyl)phenoxy]propyl acrylate (HVPA) was synthesized from p-[1-(p-hydroxyphenyl)-1-phenylethyl]phenol (HPPP), 1, 1-bis{p-[(2-oxiranyl)methoxy]phenyl}-1-phenylethane with acrylic acid and was characterized by 1H NMR, 13C NMR and FT-IR spectroscopy. The photocrosslinking studies were carried out by irradiating the mixture containing the prepolymer, HVPA (75%), with the diluent, tri(ethyleneglycol)diacrylate (25%), in the presence of a photoinitiator, Irgacure 651 (DMPA), under medium pressure mercury vapour lamp at various time intervals and various DMPA concentrations. The kinetics of the photopolymerization, percent double bond conversion and the rate of polymerization of the photocrosslinked polymers were studied using FT-IR spectroscopy. The result showed that an increasing DMPA concentration increases percent double bond conversion. The effect of viscosity of system on kinetics of photopolymerization was studied. It was found that percent double bond conversion increased with decrease in the viscosity of the system. The percent gel content and hardness of the photocrosslinked polymers were studied, and it was observed that the percent gel content and hardness of the photocrosslinked polymers were increased with increasing irradiation time and DMPA concentration. The photopolymerization studies of the synthesized prepolymer, HVPA, were compared to the commercial prepolymer, bisphenol-a-glycerolate (1-glycerol/phenol) diacrylate (BISGA). The results showed that percent double bond conversion of synthesized prepolymer, HVPA, was higher than commercial prepolymer, BISGA. This showed that HVPA was more suitable for industrial applications than BISGA.