コアーシェル型複合微粒子を用いた耐衝撃アクリル樹脂の調製と物性

摘要

PMMAは高分子材料としては高強度で，かつ高い透明 性を有することから歯科材料として広く用いられている． しかし天然歯と比較すると，力学特性，特に耐衝撃性に 劣ることが問題となっている．%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.