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针对柔性聚合物基导电复合材料的导电性差和柔性差这2个关键问题,分别从导电填料的柔性化及降低填料含量2方面着手,以脱氧核糖核酸(DNA)大分子链作为模板,制备了大小均一、链状排列的柔性纳米Ag链及纳米Ag链填充的聚氨酯基柔性导电复合材料。利用SEM对纳米Ag链/Ag包Cu粉/聚氨酯导电复合材料的界面结构进行了表征,探讨了纳米Ag链/Ag包Cu粉/聚氨酯导电复合材料导电性及柔性的机制。研究发现:保持导电填料总质量分数为76%、纳米Ag链的质量分数为4%时,纳米Ag链/Ag包Cu粉/聚氨酯导电复合材料的电阻率及形变前后的电阻变化比值达到最佳值,分别为2.13×10-4Ω·cm和3.6;当以纳米Ag链为单一填料时,制得的纳米Ag链/聚氨酯导电复合材料具有优异的柔性;泡沫法制备的纳米Ag链/聚氨酯导电复合材料可以在低填料质量分数时达到更高的导电性,当纳米Ag链质量分数为60%时,方阻为56Ω/sq,低于共混法制备的填料质量分数为65%时的纳米Ag链/聚氨酯导电复合材料(98Ω/sq)。
Aiming at the two problems of poor conductivity and poor flexibility of flexible polymer-based conductive composites, from the aspects of flexibility of the conductive filler and the reduction of the filler content, two sets of DNA macromolecular chains were used as templates to prepare Uniform size, chain-like flexible nano-Ag chain and nano-Ag chain filled polyurethane-based flexible conductive composite. The interface structure of nano-Ag chain / Ag-coated Cu powder / polyurethane conductive composites was characterized by SEM, and the mechanism of conductivity and flexibility of nano-Ag chain / Ag-coated Cu powder / polyurethane conductive composites was discussed. The results showed that the resistivity of nano-Ag chains / Ag Cu / polyurethane composites reached the best when the total mass fraction of conductive fillers was 76% and the mass fraction of nano-Ag chains was 4% Value of 2.13 × 10-4Ω · cm and 3.6, respectively. When Ag nano-Ag was used as a single filler, the nano Ag chain / polyurethane conductive composite prepared by this method had excellent flexibility. The Ag nano-chain / polyurethane conductive When the mass fraction of nanosilver Ag chain was 60%, the square resistance was 56Ω / sq, which was lower than that of nanostructured nanocomposites Ag chain / polyurethane conductive composite (98Ω / sq).