超高分子量聚乙烯基导电复合材料的电性能和自发热性能的研究

超高分子量聚乙烯(UHMWPE)具有优异的综合性能,本文采用凝胶结晶溶液方法制备了分别以碳纤维(CF)和镀镍碳纤维(NiCF)为导电填料,UHMWPE为基体的3个系列导电聚合物复合材料—UHMWPE/CF、UHMWPE/NiCF和UHMWPE/EMMA/CF复合体系,并分别对它们进行了室温伽马射线辐射处理,重点研究了这些材料的电性能和自发热性能,利用DSC、SEM、WAXS、DMA和体积膨胀等仪器进行了一系列测试表征。结果表明,NiCF作为导电填料时体系的逾渗阈值最低,为3vol%。伽马射线辐射处理不仅能有效提高材料的PTC效应,而且在合适的辐射剂量时也能有效提高材料的自发热性能。对材料介电性能的研究揭示了材料的交流电阻率与温度、频率的依赖关系。

Study on Electrical and Self-heating Properties of Ultra-high Molecular Weight Polyethylene-based Conductive Composites

Ultra-high molecular weight polyethylene(UHMWPE) possesses outstanding properties.Carbon fiber(CF) and nickel carbon fiber(NiCF) filled UHMWPE blends of UHMWPE/CF,UHMWPE/NiCF and UHMWPE/EMMA/CF composites were prepared by gelation/crystallization method,and after then gamma ray irradiation was performed on which at room temperature.The attention was focused on the electrical and self-heating properties of composites.Such equipment as DSC,SEM,WAXS and DMA were utilized to measure and characterize the composites.Results demonstrated that minimum percolation threshold value of 3vol% was obtained for UHMWPE/NiCF composites with NiCF as filler.Suitable level of gamma ray irradiation is effective to improve both the PTC effect and self-heating properties of composites.The dielectric properties of composites revealed the relationship between AC resistivity,temperature and frequency.