Roland Reeb

Kinetics of photocrosslinking reactions of a DCPA/EA matrix in the presence of thiols and acrylates

The crosslinking efficiency and kinetics of a solid acrylic copolymer DCPA/EA (dicyclopentenyl acrylate/ethyl acrylate) matrix were investigated in the presence of pentaerythritol tetrakis (2-mercaptoacetate) (PETMP) or pentaerythritol tri- and tetraacrylates used as multifunctional crosslinking agents. The reaction of thiol and acrylate addition was sensitized by benzophenone (BP). The crosslinking efficiency of the DCPA/EA—BP—PETMP copolymer system, illuminated at high wavelengths (λ > 310 nm), was compared with that of the DCPA/EA matrix alone and the 2-component system copolymer DCPA/EA–BP. The concentrations of photosensitizer and crosslinking agent were varied from 1 to 10 mass %. The kinetics of tetrafunctional thiol addition and cyclopentene (pendant group of the DCPA/EA matrix) disappearance was followed through Fourier transform infrared (FTIR) and by determining the gel content.