不同碳粒子填充液体硅橡胶的制备及性能

将不同形貌的碳粒子加至双组分室温加成型硅橡胶中制备了填充型液体硅橡胶,研究了多壁碳纳米管(MWCNTs)、炭黑(CB)和石墨烯(GR)3种填料对填充型液体硅橡胶制备工艺和使用性能差异性的影响,探究了填料用量对硅橡胶固化反应程度、体积电阻率和力学性能的影响。结果表明,MWCNTs和GR对硅橡胶固化具有阻滞延迟效果,CB则无明显的阻滞延迟效果;固化动力学上的显著差异与碳粒子表面官能团的差异性无关,而与碳粒子在体系中的分散状态直接相关,碳粒子分散状态越好,对硅橡胶的阻滞作用越弱。MWCNTs和GR的最大可用量小于CB,CB作为填料时,液体硅橡胶具有优异的加工性能和使用性能。当CB的质量分数为3.0%时,硅橡胶的体积电阻率小于107Ω·cm,拉伸强度则大于4 MPa,这表明CB在明显提升导电性能的同时,不影响力学性能。

Preparation and properties of liquid silicone rubber with different carbon particles

The filled-type liquid silicone rubbers were prepared by the addition of carbon particles with different morphologies to two-component silicone rubber.The differences in the preparation process and performances of filled-type liquid silicone rubbers with multi-walled carbon particles(MWCNTs),carbon black(CB)and graphene(GR)were studied.The effect of the amount of filler on curing rate,volume resistivity and tensile property of silicone rubber was investigated.The results showed that MWCNTs and GR had retardation effect on the curing of silicone rubber,but CB did not.The significant difference was not due to the difference in surface functional groups of carbon particles,but directly related to the dispersion of carbon particles.The better the dispersion state of the carbon particles,the weaker the retardation effect on the silicone rubber.The maximum incorporation amount of MWCNTs and GR was less than that of CB,which could be selected as the filler of silicone rubber that had excellent processing and use properties.When mass fraction of CB was 3.0%,the volume resistivity of silicone rubber was less than 107Ω·cm and the tensile strength was more than 4 MPa,which indicated that CB could significantly improve electrical conductivity without affecting mechanical properties of the silicone rubber.