脱氢型氟硅密封剂耐温耐油性能的研究

Study on temperature and oil resistance of dehydrogenated fluorosilicone sealant

以氟硅液体橡胶作为生胶,含氢硅油为硫化剂,二醋酸二丁基锡为催化剂,制备了室温硫化氟硅密封剂。研究了无机填料对密封剂力学性能和耐高温性能的影响,并探讨了硫化剂/催化剂的添加比例。研究结果表明:以25份R8200气相二氧化硅为补强填料,当硫化配比为100份氟硅液体橡胶、1.15份含氢硅油和0.16份催化剂时较优;密封胶在300℃老化100 h后,仍旧保留70%的断裂伸长率;7 d、60℃的燃油浸泡后,密封胶的质量变化率为11.3%,体积变化率为29.6%。

The room temperature vulcanized fluorosilicone sealant was prepared by using fluorosilicone liquid rubber as raw rubber,hydrogen-containing silicone oil as vulcanizer and dibutyltin diacetate as catalyst.The effect of inorganic fillers on the mechanical properties and high temperature resistance of sealant were studied,and the addition ratio of vulcanizer and catalyst was also studied.The research results showed that 25 phr fumed silica R8200 was used as reinforcing filler,and the optimum vulcanization ratio was 100 phr fluorosilicone liquid rubber,1.15 phr hydrogen-containing silicone oil and 0.16 phr catalyst.After the sealant was aging at 300℃for 100 h,70%of elongation at break was still retained.After soaking in fuel oil at 60℃for 7 d,the mass change rate and volume change rate of sealant were 11.3%and 29.6%,respectively.