Physical and mechanical properties of dental nanocomposites composed of aliphatic epoxy resin and epoxidized aromatic hyperbranched polymers

Abstract Aliphatic epoxy resin (UVR6105) and epoxidized aromatic hyperbranched polymers (HBP) were used as dental resin matrixes, siliane‐treated inorganic nanoparticles as inorganic fillers, ethyl 4‐dimethylaminobenzoate, camphorquinone, and 4‐[(2‐hydroxytetradecyl)oxy] phenyl‐phenyliodoniumhexafluoroantimonate (CD1012) as initiators to formulate new kinds of dental nanocomposites. Their physical and mechanical properties were tested and the inner structure was observed by using scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The 7 series thermal analysis system was used to determine the glass transition temperature of dental resins. Compressive strengths of dental nanocomposites are lower, diametral tensile strengths are comparable with, flexural strengths are higher than those of commercial hybrid composite (Spectrum‐TPH). The addition of HBP decreased the glass transition temperature of aliphatic epoxy resin. SEM photo micrograph shows that the nanoparticles were well dispersed and inlayed in the resin matrixes. TEM photo micrograph shows that the inner structure of dental resins presents club‐shaped. Epoxidized aromatic hyperbranched polymer can strengthen and toughen aliphatic epoxy resin. These nanocomposites are potential for dental application. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers