SYNTHESIS OF BISGMA DERIVATIVES, PROPERTIES OF THEIR POLYMERS AND COMPOSITES

2,2-Bis[4-(2 hydroxy-3-methacryloyloxy propoxy) phenyl] propane (BisGM A) is commonly the main component of the organic matrix of dental fill ing materials. Derivatives of BisGMA were synthesized from the diglyci dyl ether of Bisphenol A (DGEBA) by the parallel reaction with methacr ylic acid (MAA) and isophthalic acid as well as mixtures of methacryli c anhydride with palmitic acid and acetic anhydride, respectively, whe reby MAA was partially substituted by the latter components. By this t echnique the structure of BisGMA monomer could be varied with regard t o weight content of C=C double bonds, the hydrophilicity of the molecu le as well as its flexibility or stiffness. Free-radical initiated hom opolymerization of the monomers was carried out at 80 degrees C. Compo sites, prepared from mixtures of monomers with triethylene glycol dime thacrylate (TEGDMA) filled with 76% silica were room temperature polym erized using both redox and photoinitiated techniques. The polymerizat ion shrinkage, diffusion coefficients of water in the crosslinked poly mer, and some thermal properties of the homopolymers were determined. Mechanical properties of the resulting polymers and composites are com pared to those of BisGMA itself.