Abstract
New type composites composed of methyl methacrylate and rigid siloxane polymers, which have a ladder-like structure, have been developed for denture base resins. The Polymers prepared at various rations of 3-methacryloxypropyl trimethoxysilane and phenyl triethoxysilane were white powder, with molecular weights of 10,000 to 20,000. Compressive, diametral tensile and bending strength of the various PMMA composites which contained 10 to 15wt% of the siloxane polymers, were 20 to 40% higher than those of polymethylmethacrylate. However, the bending strength and bending modulus of PMMA composites were 20 and 15% higher, respectively than those of the copolymers with same amount of polyfunctional monomers, such as TMPT and Bis-GMA. In view of the degree of crosslink in the various copolymers and the structures of siloxane bond, it is speculated that the copolymer is reinforced not only by cross-linkage with the olefinic double bonds, but by the contribution of rigid ladder structure of the siloxane polymers. The results suggest that the molecular composites of the siloxane polymer-PMMA can be extended to denture base resins.
