Structures And Properties Of Different Dimensional Nanofillers/Silicone Rubber Nanocomposites

As an important member of high performance rubber, silicone rubber is irreplaceable in modern high-tech, aero-space and the other fields. Silicone rubber is a kind of polymer with a backbone of"Si-O"units and side chains of organic groups, which shows apparent differences in structure and performance with polymers which have a backbone of"C-C"units. Because silicone rubber is a typical semi-inorganic and semi-organic polymer, it possesses both heat resistance of inorganic matter and flexibility of organic polymer. Silicone rubber keeps good performance of cold resistance, electrical insulation and weather resistance, and it is widely applied as elastic materials under high temperature environment due to the most prominent property of thermal stability. Zero-dimensional nano-powder aero-silica is usually adopted as reinforcing agents of silicone rubber and there have been more and more researches on the other nano-materials in recent years.The composite"preparation methods-structure-property"relationship was based in this paper. High temperature vulcanized silicone rubber nanocomposites (carbon nanotubes/silicone rubber and montmorillonite/silicone rubber) were prepared by various preparation methods. Influences that preparation methods and nano-filler on mechanical property, electrical property, cross-linked network, thermal stability and the other properties of silicone rubber were studied in this paper.The result indicates that one-dimensional carbon nanotubes of wet mixed composite display favorable dispersion in the matrix of silicone rubber, which can improve the mechanical property to some extent. After surface chemical modification with KH550, carbon nanotubes have stronger force with silicone rubber and gain better enhancement. Smaller length-diameter ratio improves the tensile properties while larger ratio means better tear strength of silicone rubber. Dielectric property and thermal stability have certain increase through adding of carbon nanotubes.For the two-dimensional layered silicate montmorillonite, large enough layer spacing and intercalation driving force are necessary conditions for the preparation of montmorillonite/silicone rubber intercalated composite. Intercalated composite can be produced by melt blending of D1821 treated montmorillonite and silicone rubber. Compared with the filling structure, intercalation structure can improve the mechanical property more obviously and maintain swelling resistance of silicone rubber. However, properties of heat resistance and electrical insulation get slight deterioration.