Synthesis and physical properties of polyfunctional methacrylates (part 4). Synthesis and physical properties of aromatic dimethacrylate copolymers.

INTRODUCTION Most commercial dental resinous materials have various types of dimethacrylates, such as aromatic, alkylene, and urethane, as major monomeric ingredient. However, the relationship between the chemical structure and the physical properties has not been established. The previous papers1,2) described that in order to improve the physical properties of dental resinous materials, two aromatic dimethacrylate monomers containing sulfonyl diphenol backbone, 2, 2'-bis (4-methacryloxy phenyl) sulfone (SDMA) and 2, 2'-bis (4-methacryloxy ethoxy phenyl) sulfone (MEPS), were synthesized. In that paper, the relationships between their chemical structure and physical properties of these dimethacrylates were investigated. Consequently, the physical properties of dimethacrylate copolymers with methyl methacrylate (MMA) increased by increasing the molar ratio of these dimethacrylates. Thus, it was shown that these dimethacrylates were useful for improving the physical properties of dental resinous materials. However, these dimethacrylates were crystalline solids with a high melting point and showed relatively low solubility with MMA or other conventional dental methacrylate monomers. We synthesized eight kinds of aromatic dimethacrylates with different backbones, hydroquinone, bisphenol A (isopropylidene diphenol), bisphenol S (sulfonyl diphenol) and biphenyl, and investigated the relationship between the chemical structure and the physical properties of these dimethacrylates.