期刊Electron-beam curing of epoxy resins- Effect of alcohols on cationic polymerization.pdfVIP

Bull. Mater. Sci., Vol. 28, No. 6, October 2005, pp. 603–607. © Indian Academy of Sciences. Electron-beam curing of epoxy resins: effect of alcohols on cationic polymerization N N GHOSH* and G R PALMESE† Chemistry Group, Birla Institute of Technology and Science, Pilani (Goa Campus), Zuarinagar, Goa 403 726, India †Department of Chemical Engineering, Drexel University, USA MS received 31 December 2004; revised 5 August 2005 Abstract. Electron-beam (e-beam) induced polymerization of epoxy resins proceeds via cationic mechanism in presence of suitable photoinitiator. Despite good thermal properties and significant processing advantages, epoxy-based composites manufactured using e-beam curing suffer from low compressive strength, poor inter- laminar shear strength, and low fracture toughness. A detailed understanding of the reaction mechanism in- volving e-beam induced polymerization is required to properly address the shortcomings associated with e- beam curable resin systems. This work investigated the effect of hydroxyl containing materials on the reaction mechanism of e-beam induced cationic polymerization of phenyl glycidyl ether (PGE). The alcohols were found to play important roles in polymerization. Compared to hydroxyl group of aliphatic alcohol, phenolic hydroxyl group is significantly less reactive with the oxonium active centre, generated during e-beam induced polymerization of epoxy resin system. Keywords. E-beam; cationic polymerization; epoxy resin; size exclusion chromatogram. 1. Introduction