脱酸型低模量室温硫化硅橡胶的研制

Preparation of Low Modulus Deacidified RTV Silicone Rubber

以 α , ω - 二羟基聚二甲基硅氧烷 (107硅橡胶 )为基料,气相法二氧化硅为补强填料,甲基三乙酰氧基硅烷为交联剂,二叔丁基二乙酰氧基硅烷为扩链剂,二甲基硅油为增塑剂,二月桂酸二丁基锡为催化剂,制得单组分脱酸型低模量室温硫化硅橡胶。研究了气相法二氧化硅种类和用量、107硅橡胶黏度、扩链剂和增塑剂用量对硅橡胶性能的影响。结果表明,较佳的制备条件为100份黏度80 000 mPa · s的107硅橡胶为基料,15份气相法二氧化硅QS20为补强填料,添加4份扩链剂和20份增塑剂,此时制得的硅橡胶性能较佳,表干时间为15 min,邵尔A硬度为11度,拉伸强度为1.68 MPa,拉断伸长率为818%,100%定伸模量为0.16 MPa。

One-component deacidified low modulus RTV silicone rubber was prepared with α,ω - dihydroxy polydimethylsiloxane (107 silicone rubber ) as the base material, fumed silica as the reinforcing filler, methyltriacetoxysilane as the crosslinking agent, di-tert-butyl diacetoxysilane as the chain extender, dimethyl silicone oil as plasticizer, and dibutyltin dilaurate as catalyst. The effects of the fumed silica, the viscosity of 107 silicone rubber, chain extender and plasticizer on the properties of deacidified RTV silicone rubber were investigated, respectively. The optimum preparation conditions are as follows: 100 phr of 80000 mPa · s 107 silicone rubber, 15 phr of fumed silica QS20 as reinforcing filler, 4 phr of chain extender and 20 phr of plasticizer. The prepared deacidified RTV silicone rubber has the properties of 15 min of tack-free time, Shore hardness of 11A, the tensile strength of 1.68 MPa, the tensile elongation at break of 818%, and the 100% constant modulus of 0.16 MPa.