碳系填充型导电聚氨酯弹性体性能研究

Study on property of carbon filled conductive polyurethane elastomer

以预聚体法制备了导电聚氨酯弹性体,分析了乙炔炭黑、超导炭黑、多壁碳纳米管和纳米石墨4种导电填料以不同含量在复合材料中的内部结构形态,并研究了复合材料的体积电阻率、力学性能及热稳定性。通过分析添加量与体积电阻率的关系得到4种复合材料的渗滤阈值,对比分析了复合材料的硬度、拉伸强度和扯断伸长率,采用热重分析仪对热分解过程进行研究和探讨。结果表明:导电填料粒径越小,比表面积越大,可在较低含量时达到渗滤阈值。添加多壁碳纳米管的复合材料,其力学性能得到有效提高。在最大失重阶段的热分解上,超导炭黑填充型材料分解温度为435±3℃,较其他复合材料高20℃左右,具有较好的高温热稳定性。

Conductive polyurethane elastomers were prepared by the prepolymer method.The internal structure and morphology of acetylene black,superconducting carbon black,carbon nanotubes,nano-graphite fillers with different contents in composites were analyzed,and studied the volume resistivity,mechanical properties and thermal stability of them.The percolation thresholds of 4 kinds of composites were obtained by analyzing the relationship between the add amount and volume resistivity.The hardness,tensile strength,elongation at break of composites were compared and analyzed.Thermal gravimetric analyzer(TGA)was used to study and discuss the thermal decomposition process.The results indicated that the smaller the conductive filler particle size was,the greater the specific surface area was,and the percolation threshold can be reached at lower levels.The mechanical properties of composites with carbon nanotubes were improved effectively.The decomposition temperature of superconducting carbon black filled composites was 455±3℃,which was about 20℃ higher than other composites and had better thermal stability at high temperature.