正交试验法优化铂催化液体硅橡胶导电发泡材料

Optimization of platinum catalyzed liquid silicone rubber conductive foam by orthogonal experiment

液体硅橡胶(LSR)除了具有硅橡胶的优势,还具有良好的流动性,易于加工,绝缘性限制了其在电子领域的应用。目前已有许多导电固体硅橡胶的研究,但国内关于导电LSR的研究较少,且都有一些共性问题,比如导电填料过多、硬度太高、密度过大等。为了降低铂催化LSR的导电填料添加量,并降低其密度和硬度,采用乙炔炭黑(CB)作为导电填料并将材料进行发泡,制备LSR导电发泡材料。但是,铂催化LSR还有无法使用常规含氮有机发泡剂以避免铂中毒的问题,因此需要采用其他发泡方法。因而采用羟基硅油(Si-OH)和水作为化学及物理发泡剂,蒙脱土(MMT)作为补强剂,为了得到综合性能良好的硅橡胶导电发泡材料,利用正交试验法,并进行单因素方差分析,研究了Si-OH,CB,MMT和水对材料发泡和力学性能及电导率的影响。结果表明,正交试验法可快速得到CB/LSR导电发泡最优配比:当LSR质量分数为56.1%,Si-OH为28.1%,CB为7%,MMT的质量分数为5.3%,水的质量分数为3.5%时,制备的发泡材料电导率为3.36×10^(-6)S/m,液体硅橡胶比纯LSR提高了9个数量级,密度为0.67 g/cm^(3),相比纯LSR降低了43%,邵C硬度为36,比纯LSR降低了33%。

Liquid silicone rubber(LSR)not only has the advantages of silicone rubber,but also has good fluidity and is easy to process.However,its insulation properties limit its application in the electronic field.At present,there have been many studies on conductive solid silicone rubber,but there is relatively less research on conductive LSR,and there are still some common problems,such as excessive conductive fillers,high hardness,and high density.In order to reduce the amount of conductive filler,also reduce its density and hardness,acetylene carbon black(CB)was used as the conductive filler and the material was foamed to prepare conductive LSR foam.However,platinum catalyzed LSR cannot use conventional nitrogen-containing organic foaming agents to avoid platinum poisoning,so other foaming methods need to be used.Hydroxy silicone oil(Si-OH)and water were used as chemical and physical foaming agents,and montmorillonite(MMT)as a reinforcing agent.In order to obtain a silicone rubber conductive foam with good comprehensive performance,the orthogonal experimental method was used and one-way analysis of variance was conducted to study the effects of hydroxy silicone oil,CB,MMT and water on foaming,mechanical properties,and electrical conductivity of the material.The results show that the orthogonal experimental method can quickly obtain the optimal ratio of CB/LSR conductive foam:when LSR content is 56.1 wt%,Si-OH is 28.1 wt%,CB is 7 wt%,MMT is 5.3 wt%,water is 3.5 wt%,the electrical conductivity of the prepared foam material is 3.36×10^(-6)S/m,which is 9 orders of magnitude higher than pure LSR,with density of 0.67g/cm^(3),43%decrease compared to pure LSR,Shore C hardness of 36,and 33%decrease compared to pure LSR.