Synthesis of silica-polymer core-shell hybrid materials with enhanced mechanical properties using a new bifunctional silane-based photoinitiator as coupling agent

International audienceHere, we report the use of new bifunctional silane-based type-1 photoinitiator (SPI-1) as a coupling agent for photopolymer filler and silica grafting. The SPI-1 is grafted on the surface of silica nanoparticles via interactions between the ethoxy group of the silane and the silanol groups of the silica surface. The grafted particles are then dispersed or embedded in/with acrylate polymer by a direct photopolymerization process. The materials were characterized using different techniques including UV–vis spectroscopy, FTIR, TGA, and TEM. Their mechanical properties and the surface morphology were also investigated using AFM and DMA analyses. A significant change and enhancement of the mechanical properties of the newly synthesized materials were observed with respect to that of the unmodified silica. The analysis of the morphology at the microscale level reveals interesting information on the origin of this enhancement and on the dispersion of the filler in the polymer matrix