Synthesis,characterization and polymerization characteristics of new dimethacrylates,derived from 3,3,5‐trimethylcyclohexan‐1‐one–phenol adducts,as monomers for dental composites

The object of this study was to synthesize, characterize and evaluate several new dimethacrylate monomers, in order to discover new compositions for possible formulation of improved dental restoratives. Dimethacrylates derived from the 3,3,5‐trimethylcyclohexan‐1‐one–phenol reaction products were prepared and characterized by Fourier transform infrared and nuclear magnetic resonance. Thermal‐ and photopolymerization characteristics of these experimental monomers, in blends with triethyleneglycol dimethacrylate (TEGDMA), were evaluated by differential scanning calorimetry and differential photocalorimetry. An additional dimethacrylate derived from the 3,3,5‐trimethylcyclohexanone–phenol adduct, supplied by Bayer AG, was also evaluated during the study. A control for comparison consisted of a 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloyloxy‐propyl) phenyl]propane (BisGMA) blend with TEGDMA. It was found that the polymerization behavior and properties of the visible light‐cured neat resins were dependent on their chemical structures. The experimental resins exhibited comparable curing characteristics, lower water sorption, higher wet glass transition temperature, and other improved properties, compared with the polymerized BisGMA/TEGDMA control. The more rigid and hydrophobic nature of the experimental resins, accomplished by incorporation of the bulky trimethyl‐substituted cyclohexyl moiety in the novel dimethacrylates, was considered to be the major factor contributing to the improved properties. These new dimethacrylates, for formulating thermosets with lower water sorption and higher glass transition temperature, may offer a path to improving composites for a variety of applications, including such things as dental restoratives and bone cements. Copyright © 1999 John Wiley & Sons, Ltd.