【摘要】 以聚醚型热塑性聚氨酯(TPU)为基体、导电炭黑(CB)作为填料,通过熔融共混法制备了CB/TPU导电复合材料。探究了CB含量对材料的电性能、力学性能、微观形貌和热稳定性的影响。结果表明:电阻率随CB质量分数变化的反S曲线符合导电通路理论,在CB质量分数为10%～14%范围内电阻率下降了9个数量级,同时介电性能也发生了显著变化;适量的CB能够增强材料的力学性能,当CB质量分数为4%时拉伸强度和断裂伸长率分别达到最大值53.8 MPa和1 066.7%,并且拉伸模量随着CB质量分数的增加而增大;CB的加入对材料的热稳定性无明显影响。更多还原

【Abstract】 The CB(carbon black)/TPU(thermoplastic polyurethane) conductive composite was prepared by melt blending with using TPU as the matrix and conductive CB as the filler. The experimental temperature was 185 °C, the speed was 60 r/min with the CB/TPU mixture in a torque rheometer for 5.5 min and then pressed by a flat vulcanizer.The effects of CB content on electrical or dielectric properties, mechanical properties, microstructure and thermal stability of the materials were investigated. The relationship between the logarithmic resistivity and the amount of added carbon black was in accordance with the conduction path theory. When the CB mass fraction was less than 10%,the decrease of resistivity was not obvious; when the mass fraction of added CB was increased from 10% to 14%, the resistivity of the CB/TPU composite was decreased sharply by 9 orders of magnitude, and the percolation zone of the CB/TPU material was between 10% and 14%; when the CB mass fraction was increased to be more than 16%, the resistivity was decreased slowly and reached a steady state, which were highly consistent with the classical inverse Sshaped percolation curve in region Ⅰ, Ⅱ and Ⅲ, respectively. As the CB mass fraction increased, the dielectric loss,dielectric constant and AC conductivity of the material were increased, the tensile strength and elongation at break of CB/TPU were increased first and then decreased, and ultimately reached the maximum values of 53.8 MPa and 1066.7%, respectively. When the CB mass fraction was 4%, the tensile modulus was improved with the increase of CB mass fraction. The tensile fracture morphology of CB/TPU was changed from "river-like" morphology to high-lowstaggered fracture stretching, and the conductive path was observed in SEM. The addition of CB improved the thermal stability of CB/TPU composites.更多还原