CURE MONITORING OF PHOTOSENSITIVE RESINS BY PHOTO-DYNAMIC MECHANICAL ANALYSIS

A new technique, photo-dynamic mechanical analysis, was developed to m onitor the cure of photosensitive resins. In this technique, the resin is dispensed on a low modulus substrate and the force needed to maint ain a prescribed elongation on the sample is measured while the sample is exposed to an ultraviolet source. The force increases with the ext ent of cure and reaches a plateau when the resin is fully cured. Photo -dynamic mechanical analysis was found to be a rapid, continuous, and reliable technique to monitor the extent of cure of photopolymerizable resins. A finite element analysis was developed to calculate the resi n modulus from the experimental force data. Thus, it was possible to m onitor the resin modulus from the liquid state to the solid state.