Preparation of CaCO₃-SiO₂ composite with core-shell structure and its application in silicone rubber

A new CaCO₃-SiO₂ composite with core-shell structure was successfully prepared by mechano-chemistry method (MCM). SEM and FTIR indicated that SiO₂ particles were homogeneously immobilized on the surface of CaCO₃. The well dispersion of this CaCO₃-SiO₂ composite into silicone rubber can not only reduce the usage amount of SiO₂, but also improve the mechanical properties of silicone rubber. By the calculation, the theoretical numbers of the SiO₂ particles is about 10 times as large as that of CaCO₃ particles in the CaCO₃-SiO₂ composite. Mixing CaCO₃-SiO₂ composite in silicone rubber can enhance the breaking strength of the silicone rubber about 18% as high as that when mixing the pure SiO₂. And the elongation at break is about 14% less than that of adding the pure SiO₂ sample.