多尺度改性航空硅橡胶宽温域阻尼材料

Multi-scale modification of aerospace silicone rubber damping material with wide temperature range

硅橡胶在宽温域内性能稳定,是航空领域开发阻尼降噪技术的首选材料,然而其在有效阻尼温域内的阻尼因子较小,阻尼性能有限,需要进行多尺度改性。首先进行分子尺度改性,改变乙烯基含量和烷基氢硅烷加入量两个因素调控分子结构,考察其对硅橡胶力学性能和阻尼性能的影响。结果表明,乙烯基侧链的生长和烷基氢硅烷在乙烯基侧链的成功接枝提高了分子链段的运动壁垒,增强了硅橡胶的阻尼性能,乙烯基含量为15%(质量分数,下同)、烷基氢硅烷与乙烯基摩尔比为3∶1时,硅橡胶表现出最佳的阻尼性能。以此为基础继续进行微观尺度改性,通过红外光谱表征苯基含氢硅油的成功合成,并考察其添加量对硅橡胶阻尼性能的影响。结果表明,添加适量的阻尼剂苯基含氢硅油可以通过形成π-π强相互作用力和增加松弛时间的协同作用提高能量吸收效率,阻尼剂添加量为2%时,硅橡胶表现出最佳的阻尼性能。分子尺度和微观尺度的有效协同显著增强硅橡胶的阻尼性能,多尺度改性策略适用于制备硅橡胶宽温域阻尼材料。

Silicone rubber has stable performance in a wide temperature range.However,as its damping factor in the effective damping temperature range is small and the damping performance is limited,multi-scale modification is required.Firstly,the molecular scale modification was carried out,and the molecular structure was adjusted by changing the vinyl content and the addition amount of alkylhydrosilane.The results show that the growth of the vinyl side chain and the successful grafting of the alkyl hydrogen silane on the vinyl side chain increase the barrier of motion of the molecular chain and enhance the damping performance of the silicone rubber.When the vinyl content is 15%(mass fraction,the same as below)and the molar ratio of hydrosilane to vinyl is 3∶1,silicone rubber exhibits the best damping performance.On this basis,the micro-scale modification was continued.The results showed that adding phenyl hydrogen-containing silicone oil improved energy absorption efficiency because of the synergistic effect of formingπ-πstrong interaction bonds and increasing relaxation time.When the damping agent is added at 2%,silicone rubber exhibits the best damping performance.The effective synergy of molecular scale and micro scale significantly enhances the damping performance of silicone rubber,and the multi-scale modification strategy is suitable for preparing damping silicone materials with wide temperature range.