脱醇型单组分室温硫化硅橡胶的制备

Preparation of Dealcoholized One-Component RTV Silicone Rubber

为解决脱醇型室温硫化硅橡胶存在的黏度高峰、贮存期短、易黄变等问题,以α,ω-二羟基聚二甲基硅氧烷(107硅橡胶)为基料,添加自制醇型一体化助剂、二甲基硅油、纳米碳酸钙等,制得脱醇型单组分室温硫化硅橡胶。研究了制备工艺,活性纳米碳酸钙、二甲基硅油、自制醇型一体化助剂用量对脱醇型室温硫化硅橡胶性能的影响。结果表明,较佳配方为:300份黏度80000 mPa·s的107硅橡胶,100份黏度20000 mPa·s的107硅橡胶,40份二甲基硅油,460份活性纳米碳酸钙,40份钛白粉,60份自制醇型一体化助剂。采用此配方制得的脱醇型室温硫化硅橡胶贮存稳定性优良、耐黄变性佳、力学性能好、深层硫化速率快,其拉伸强度为1.32 MPa,拉断伸长率为503%,深层硫化时间为24 h。加速老化试验后,表干时间、深层硫化时间、外观颜色均无明显变化。

In order to solve the problems of dealcoholized vulcanized silicone rubber,such as peak viscosity,short storage period and easy yellowing,the dehydrated one-component room temperature vulcanized silicone rubber was prepared byα,ω-dihydroxypodimethylsiloxane as the base,adding homemade alcoholic integration additives,dimethyl silicone oil,nanocalcium carbonate,etc.The effects of the process,the amount of active nanocalcium carbonate,dimethyl silicone oil,and homemade alcoholic integrated additives on the performance of dealcoholized vulcanized silicone rubber were studied.The results show that the preferred formulation is:300 phr of 107 silicone rubber with a viscosity of 80000 mPa·s,100 phr of 107 silicone rubber with a viscosity of 20000 mPa·s,40 phr of dimethyl silicone oil,460 phr of active nano-calcium carbonate,40 phr of titanium dioxide,60 phr of homemade alcohol-integrated additive,the dealcoholized vulcanized silicone rubber has excellent storage stability,yellowing resistance,good mechanical properties,fast deep vulcanization speed,and the tensile strength of the product is 1.32 MPa,the elongation at break is 503%,and the curing time is 24 h.There is no obvious changes on the surface drying time,deep vulcanization time and appearance color in the accelerated aging test.