镀银铝粉/导电硅橡胶复合材料的制备与性能  

Preparation and properties of silver coated aluminum powder/conductive silicone rubber composites

作　　者：刘小艳[1] 王帮武[1] 朱巍[1] 李润源[1] 张寅[1] LIU Xiaoyan WANG Bangwu ZHU Wei LI Runyuan ZHANG Yin(Research Institute of Aerospace Materials＆ Processing Technology ,Beijing 100076,China)

机构地区：[1]航天材料及工艺研究所,北京100076

出　　处：《弹性体》2017年第1期36-41,共6页China Elastomerics

摘　　要：在硅橡胶混炼胶母胶中填充镀银铝粉制备了几种导电的硅橡胶复合材料,采用扫描电子显微镜观察了镀银铝粉在硅橡胶基体中的分散情况,考察了镀银铝粉填充量对材料微观形貌、邵尔A硬度、拉伸强度及导电性能的影响,结合导电橡胶制品对使用寿命的需求背景,分析了热空气加速老化对导电硅橡胶复合材料填料表面元素含量、物理力学性能、导电性能及电磁屏蔽效能的作用机理。结果表明,随着镀银铝粉填充量的增加,单位面积上铝粉粒子相互接触面积增大并逐渐形成挤压堆积形态;材料的邵尔A硬度逐渐增大,拉伸强度先增大而后基本保持稳定,拉断伸长率呈直线下降趋势;材料电阻率明显降低,最低可达1.2×10^(-3)Ω·cm,导电性能不断提高。经过150℃高温热空气加速老化后,材料内部镀银铝粉颗粒表面的O元素发生较明显的增大;随着老化时间的增加,邵尔A硬度和拉伸强度呈增大趋势,拉断伸长率减小,电阻率呈现规律增大的趋势,电磁屏蔽效能则呈现出相反的变化趋势。Aseries of conductive silicone rubber composites were prepared by filling silver coated aluminum powder （Si/Al powder） with different content within rubber matrix.The dispersion of Si/ Al powder was observed via scanning electron microscopy.The microstructure,Shore A hardness,tensile strength and electronic conductive properties of the prepared composites were subsequently investigated.Based on the demand background of rubber articles for long service life,the action mechanism of oven acceleration aging on the element content variation on filler＇s surface layer, the mechanical properties, electronic conductive properties and shielding effectiveness of composites were analyzed specifically.The results indicated that with the Si/Al powder content increased, the accessibility between fillers extrusion on each other increased in unit area.Also,Shore A hardness increased with the tensile strength increasing first then changing little,while the elongation ratio decreasing.The volume resistivity decreased to 1.2×10^-3Ω·cm with improved electronic conductivities.The oxygen element content on filler＇s surface increased obviously after aging in 200 ℃ oven.Shore A hardness and tensile strength increased while the elongation ration decreased with the aging time prolonged.And the resistivity increased while the shielding effectiveness presenting contrary.

关 键 词：镀银铝粉 硅橡胶 导电 电磁屏蔽 热空气加速老化 

分 类 号：TQ333.93[化学工程—橡胶工业]