Determination of the effects of cure conditions on the photopolymerizationof liquid crystalline monomers using differential photo-calorimetry

Photopolymerization of diacrylate liquid crystalline monomers has several a dvantages over thermal polymerization. Most notably, photopolymerization al lows for the cure reaction to occur at a temperature where a mesophase exis ts. In this paper we discuss the effects of several cure conditions, includ ing temperature, on the conversion and reaction rates of two liquid crystal line monomers. Each of these monomers exhibits a nematic mesophase at eleva ted temperatures. The data indicate that the presence of the mesophase has an impact on both reaction rates and conversion. Further studies concerning the effects of photoinitiator composition and concentration reveal that th ese parameters significantly influence the polymerization rate but do not a ffect the degree of conversion at extended irradiation times. (C) 1999 Else vier Science B.V. All rights reserved.