Photopolymerization of acrylates using N-aliphaticmaleimides as photoinitiators

The photopolymerization of a diacrylate monomer with an N-aliphaticmaleimid e as the photoinitiator has been investigated by photodifferential scanning calorimetry (photo-DSC), real-time infrared (RTIR) spectroscopy, and real- time UV (RTUV) spectroscopy. Photo-DSC exotherm results for relatively thic k films (similar to 150 mu m) showed an increase in the polymerization reac tivity (R) up to a concentration of only about 2 mol% N-aliphaticmaleimide. RTIR analysis was used to determine that the reactivity of a diacrylate th in film (similar to 10 mu m) increased continually as the concentration of AcOEMI increased from 0.1 to 30 mol%. Both RTIR and RTUV spectroscopy indic ated that essentially AcOEMI was completely consumed in the polymerization process, and colorless crosslinked acrylate films with little absorbance ab ove 300 nm were produced. (C) 1999 Elsevier Science Ltd. All rights reserve d.