The fracture toughness of polymeric materials and composites can be enhanced by the incorporation of polymer nanoparticles. The combination of a soft core and a hard shell leads to an improvement of the fracture toughness of the polymeric nanocomposites. Thereby the mechanical resistance of the materials is commonly decreased. In our approach core–shell nanoparticles consisting of a ethyleneglycoldimethacrylate (EGDMA) crosslinked poly(butylacrylate) (PBA) core and a poly(methylmethacrylate) (PMMA) shell were synthesized. The polymer particles were implemented in triethylene glycol dimethacrylate (TEGDMA)/urethane dimethacrylate(UDMA) based composites in order to enhance the mechanical properties. Different core–shell ratios were applied to study its influence on the fracture toughness and E-modulus. An examination of shell-crosslinking with TEGDMA up to 8% was performed to improve particle stability and redispersing ability. The particle morphologies were characterized by dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM) and analytical ultracentrifuge (AUC). Latex sizes of 70 to 220 nm were achieved. The mechanical properties (fracture toughness, E-modulus and Kmax) of polymer composites were investigated in a three-point bending test. Core/shell ratios of 50/50 showed a decreasing effect to fracture toughness, E-modulus and Kmax. Polymer particles with core/shell ratios of 30/70 lead to a significant increase of mechanical properties which make them interesting in particular for hard tissue applications like bone cements or dental replacement material.

Improvement of mechanical properties of methacrylate based composites by latex particles

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.