Differential photo-calorimetry of photopolymerizable ceramic suspensions

Suspensions of alumina powders in low-viscosity acrylate monomers were produced and their curing behaviour characterized. Although these suspensions contain 50 vol % Al2O3 particles, the viscosity is between 200 and 300 mPas. These suspensions were rendered ultraviolet-curable by the addition of photoinitiators sensitive to ultraviolet radiation. Photopolymerization kinetics were characterized via differential photo-calorimetry. Photopolymerization rates and monomer conversions were unaffected by the presence of the alumina filler. Increasing the average functionality of the monomer mixture tended to increase slightly the photopolymerization rate and decrease the final conversion. Higher concentrations of photoinitiator increased both the rate of photopholymerization and the final conversion. The presence of oxygen was shown severely to restrict polymerization in these filled systems as well. (C) 1998 Kluwer Academic Publishers.