采用甲基乙烯基硅橡胶110-2与不同苯基含量的苯基硅橡胶121-1、121-2和121-3作为生胶制备了混炼胶,并探究了硫化胶的耐高低温与耐介质性能。结果表明:121-1硫化胶与121-2硫化胶在250℃以上的耐高温性能比110-2硫化胶更好,并且表现出更优异的低温性能,它们不存在低温结晶峰,玻璃化转变温度(T_g)分别为-105℃与-85℃,-70℃时的压缩耐寒系数分别为0.49与0.46。在耐介质性能测试中,苯基硅氧烷链节的引入并没有对硅橡胶在IRM-901标准油与航空煤油RP-3的耐介质性能产生明显影响。但在磷酸酯液压油skydrol LD-4中,苯基硅橡胶的耐介质性能变差,并且随着苯基含量的增加而明显下降;采用121-1制备的吸波胶具备优异的低温性能和隐身性能,可满足宽温域吸波橡胶密封型材的使用需求。

Using methyl vinyl silicone rubber 110-2 and phenyl silicone rubbers 121-1,121-2 and 121-3 with varying phenyl contents as raw rubbers,mixing rubbers were prepared to investigate the high- and low-temperature resistance and medium resistance properties of the vulcanized rubber.It was found that the vulcanized rubbers 121-1 and 121-2 had better high-temperature resistance above 250℃ than the vulcanized rubber 110-2,along with excellent low-temperature performance.The glass transition temperatures (T_g) of phenyl silicone rubbers 121-1 and 121-2 were -105℃ and -85℃,respectively,with no low-temperature crystallization melting peaks observed,and the compression cold-resistance coefficients at -70℃ were 0.49 and 0.46,respectively.In medium resistance tests,the introduction of phenyl silicone chain did not affect the medium resistance of silicone rubber in IRM-901 standard oil and aviation kerosene RP-3.However,in phosphate ester hydraulic oil skydrol LD-4,the medium resistance of phenyl silicone rubber deteriorated and decreased significantly with the increase of phenyl content.The wave-absorbing silicone rubber prepared with 121-1 had excellent low-temperature performance and stealth performance,and satisfied the needs of the use of wave-absorbing rubber sealing profiles in a broad temperature range.