Study On The Technology Of Reinforcement And Foaming Of Liquid Silicone Rubber

In this paper, the room temperature vulcanized silicone rubber foams were prepared quickly by using different structures silicone rubbers as raw rubber and different types of silica, carbon nanotubes, potassium titanate whisker and MQ silicone resin as filler, through the dehydro-condensed of foaming method. Firstly, the relationships between the different raw rubbers, fillers and the rheology and crosslinking rate of the based-compound were investigated in detail. On the base of this above, the influences of raw rubbers and fillers on the preparation, morphology and the thermal and mechanical properties of the silicone rubber foams were further explored, respectively.The results of the relationship between the rubber structures and the rheology and crosslinking rate of the based-compound indicate that: when the viscosity of 107 silicone reaches at 3.0 Pa.s, the rheology of 107 silicone gets to an optimized value, which is fit for the preparation of the silicone rubber foams; the crosslinking rate of the based-compound increases with the increase of the viscosity of 107 silicone; when the phenyl siloxane silicone and vinylsiloxane silicone is compounded with 107 siloxane, the introduction of vinyl and phenyl groups decrease the crosslinking rate of the based-compound.The results of the relationship between the fillers and the rheology and crosslinking rate of the based-compound indicate that: the silica preparation methods and surface modification on silica have a great influence on the rheological and crosslinking rate of the based-compound. The crosslinking rate of the based-compound is promoted by using fumed silica R8200 with the surface of hydrophobic treated, whereas is decreased by using precipitated silica D17. The viscosity of the based-compound increases with addition of a few Multi-walled carbon nanotubes while decreases with addition of potassium titanate whisker and MQ silicone resin. The crosslinking rates of the based-compound decrease by filling with Multi-walled carbon nanotubes, potassium titanate whisker and the MQ silicone resin.The different raw rubbers and fillers affect the rheology and crosslinking rate of the based-compound, which then, takes some influence on the preparation, morphology and the thermal and mechanical properties of the silicone rubber foams.The results of the influence of the rubber structures on the preparation, morphology and the thermal and mechanical properties of the silicone rubber foams indicate that: the foam density of the silicone rubber foams prepared by different raw rubber are nearly the same. Silicon foam with uniform and fine cell structures can be successfully fabricated by using phenyl siloxane rubber. The mechanical properties of the silicone rubber foams can be improved by incorporating the vinyl into the siloxane. In addition, the thermal stability of silicone foam is apt to be improved by introduction of vinylsiloxane rubber and phenyl siloxane silicone.The results of the influence of the fillers on the preparation, morphology and the thermal and mechanical properties of the silicone rubber foams indicate that: the introductions of the silica, Multi-walled carbon nanotubes, potassium titanate whisker and MQ silicone resin have little influence on the cellular structure and foam density of the silicone rubber foams. However, the compatibility between fillers and silicone rubber can be decreased by filling with the Multi-walled carbon nanotubes and potassium titanate whisker. The mechanical properties of silicone foam are increased by filling with silica, Multi-walled carbon nanotubes and the MQ silicone resin, whereas decreased by using potassium titanate whisker as filler. In addition, the thermal stability of silicone foam tends to be improved by filling with silica and carbon nanotubes.