Heat of polymerization of dimethacrylate monomers investigated by isothermal DSC measurement.

Heat of polymerization of Bis-GMA-TEDMA monomer mixtures, corresponding to the conceivable constituents of composite resins, was evaluated from the area of exothermic peak in DSC curves, and also the conversions of polymerization were calculated from the ratio of the heat of polymerization for each monomer mixture to an assumed one at 100% conversion. The effects of composition of monomers and environmental atmosphere on the polymerization were examined. The results suggest that increasing amounts of TEDMA in the monomer mixtures increases the length of the inhibition period for oxygeninhibited polymerization of dimethacrylate monomers, but decreases the porosity of cured resins.