Preparation And Oil Resistance Of RTV Silicone Rubber Blends

Silicone rubber has unique molecular structure,and has many excellent properties.It has applications in many industries.However,with the continuous progress of society and the rapid development of science and technology,in the application field of multiple silicone rubber,especially in the aerospace and automobile industry,the silicone rubber is required to have excellent resistance to oil in surrounding environment.However,the traditional two methyl silicone rubber itself has poor oil resistance,and the performance decreases obviously after the oil soaked,and it can not meet the application requirements.Fluorosilicone rubber not only has the excellent performance of silicone rubber,but also has outstanding oil resistance.However,the synthetic process is difficult to control and the cost is high,so it is difficult to be widely used.This article synthesizes PTFPMS and mechanically blends it with PDMS,to which PMPS is added.Prepare low-cost,oil-resistant silicone rubber with excellent overall performance.The main contents of this paper include the following parts.In the first chapter,the classification and properties of silicone rubber are briefly introduced,and the study of improving the performance and improving the oil resistance of silicone rubber by blending silicone rubber with other rubbers are summarized.Secondly,the synthesis,structure and properties,composition and application of the fluorosilicone rubber are introduced.Finally,the purpose of polymer blending and the improvement of compatibility were introduced.In the second chapter,PTFPMS was prepared by anionic ring opening polymerization with D3F as a monomer and sodium silicate as the catalyst.The structure and molecular weight of PTFPMS were characterized by FI-IR,NMR and gel permeation chromatography.The homemade PTFPMS was blended with PDMS to study the effects of PDMS viscosity,the blending ratio of PTFPMS and PDMS,addition of fumed silica,kind and addition of crosslinking agent,addition of coupling agent and addition of catalysis on the blend,and the formula was optimized.The blend with suitable drying time and crosslinking density and good mechanical properties and oil resistance were prepared.The blend adhesive prepared by the best formula was analyzed by SEM and TGA.The results showed that the compatibility and thermal stability of the blends were better.In the third chapter,PMPS was characterized by FI-IR and NMR,and the content of the phenyl group was determined to be 19%.It was added to the blend of silicone rubber and fluorosilicone rubber.The effects of different blending processes,blending ratio,and additives,including fumed silica,crosslinking agent,coupling agents,and catalysts on the properties of the blends were discussed and the formulations were optimized.The ternary blends have excellent comprehensive properties and outstanding heat resistant oil properties.The fourth chapter summarizes the work of this thesis,and points out its shortcomings.