脱酸型RTV-1氟硅密封剂的研制

Preparation of RTV-1 Deacidified Fluorosilicone Sealant

以α,ω-二羟基聚甲基三氟丙基硅氧烷为基胶、烃基三乙酰氧基硅烷为交联剂、气相法二氧化硅为补强填料、氧化铁红为耐热添加剂、γ-(2,3环氧丙氧)丙基三甲氧基硅烷(KH 560)为增粘剂、二月桂酸二丁基锡为催化剂,制成脱酸型单组分室温硫化(RTV-1)氟硅密封剂。探讨了基胶黏度、气相法二氧化硅用量、交联剂结构及用量对密封剂工艺性能和力学性能的影响。确定的较佳配方为100份黏度19 000 mPa·s的基胶、15份甲基三乙酰氧基硅烷、20份气相法二氧化硅、5份氧化铁红、2份KH 560、1份二月桂酸二丁基锡。按此配方得到的脱酸型RTV-1氟硅密封剂的工艺性能、常温力学性能、耐高温性能、耐油性能达到或超过国外同类产品的水平。

RTV-1 deacidified fluorosilicone sealants were prepared by using α,ω-bihydroxyl polymethyl trifluoropropyl siloxane as the raw rubber,and hydrocarbyltriacetoxysilane as the cross-linker,fumed silica as the reinforcing agent,red iron oxide as the heat resistant agent,glycidoxypropyltrimethoxysilane as the tackifi-er,and dibutytin dilaurate as the catalyst. The effects of the viscosity of fluorosilicone rubbers,the content of fumed silica,the structure and content of cross-linker on the mechanical and technical properties of the sealant were studied. The preferred formulation was that 100 parts of fluorosilicone with a viscosity of 19 000 mPa·s, 15 parts of methyltriacetoxysilane,20 parts of fumed silica,5 parts of red iron oxide,2 parts of glycidoxyprop-yltrimethoxysilane,and 1 part of dibutytin dilaurate. The obtained RTV-1 deacidified fluorosilicone sealants show good mechanical properties,high temperature resistance and good oil resistance,equal to or exceeding the similar products of the foreign countries.