Differential photo-calorimetry of photopolymerizable ceramic suspensions

Suspensions of alumina powders in low-viscosity acrylate monomers were prod uced and their curing behaviour characterized. Although these suspensions c ontain 50 vol % Al2O3 particles, the viscosity is between 200 and 300 mPas. These suspensions were rendered ultraviolet-curable by the addition of pho toinitiators sensitive to ultraviolet radiation. Photopolymerization kineti cs were characterized via differential photo-calorimetry. Photopolymerizati on rates and monomer conversions were unaffected by the presence of the alu mina filler. Increasing the average functionality of the monomer mixture te nded to increase slightly the photopolymerization rate and decrease the fin al conversion. Higher concentrations of photoinitiator increased both the r ate of photopholymerization and the final conversion. The presence of oxyge n was shown severely to restrict polymerization in these filled systems as well. (C) 1998 Kluwer Academic Publishers.