Preparation and mechanical properties of impact resistance acryl resin using core-shell composite nanoparticles

PMMA is used as the most popular dental resin and show high strength and transparency, but is weak against an impact. Although introduction of rubber domain into a matrix polymer has been widely investigated to improve the impact resistance, strength and surface hardness of materials are decreased by rubber element. Therefore, in this study, the core-shell composite nanoparticles containing silica particles in rubber domain were prepared by emulsion polymerization with methyl methacrylate (MMA) and ethyl acrylate. These particles were added to MMA and bulk polymerization was carried out to obtain test specimen. The physical properties including impact resistance were evaluated by three-point bending test, falling ball impact test and Vicker's hardness test. The impact resistance of test specimen was improved in comparison with the test specimen prepared with core-shell particles without silica particle. Moreover, deterioration in mechanical properties was depressed by addition of silica particle to rubber element.