水性聚氨酯/石墨烯柔性导电复合材料制备及性能

Preparation and Properties of Waterborne Polyurethane/Graphene Flexible Conductive Composites

针对石墨烯在与聚合物基体复合中出现的难以均匀分散、易出现团聚的问题,通过采用不同的分散剂对石墨烯进行非共价键功能化改性,选取最佳分散剂,以制备稳定的石墨烯分散液。通过溶液共混法和流延浇铸法将石墨烯均匀分散在水性聚氨酯(WPU)基体中,制备了WPU/石墨烯柔性导电复合材料。溶剂分散效果及吸光度测试结果显示,聚乙烯醇(PVAL)水溶液对石墨烯的分散能力强,制备的石墨烯分散液较为稳定,且PVAL水溶液的最佳质量分数是15%,其吸光度达到2.943;导电性能测试结果发现,石墨烯含量为WPU质量的2%时,WPU/石墨烯柔性导电复合材料综合性能较好,其电导率为2.6×10^(-7)S/m,并在此基础上,考察发现WPU∶PVAL水溶液质量比为80∶20时,复合材料的拉伸强度较未加分散剂的增加了116%,电导率为4.5×10^(-5)S/m,较未加分散剂的增加了5个等级;扫描电子显微镜结果表明,加入PVAL水溶液后,石墨烯能均匀地分散在WPU基体中,表明PVAL水溶液对石墨烯具有良好的分散作用。

In order to solve the problem that graphene is difficult to disperse uniformly and easy to agglomerate in the composite with polymer matrix,different dispersants were selected to modify the graphene by non-covalent bond functionalization,and the best dispersant was selected to prepare stable graphene dispersion.Graphene was uniformly dispersed in waterborne polyurethane(WPU)matrix by solution blending and casting method to prepare WPU/graphene flexible conductive composites.The solvent dispersion effect and absorbance test results show that the polyvinyl alcohol(PVAL)aqueous solution has strong dispersion ability for graphene,and the prepared graphene dispersion is relatively stable.The optimum solution concentration of PVAL aqueous solution is 15 wt%,and the absorbance reaches 2.943.The results of conductivity study show that when the graphene content is 2%of WPU mass,the comprehensive performance of WPU/graphene flexible conductive composite is better,and its conductivity is 2.6×10^(-7)S/m.On this basis,it is found that when the mass ratio of WPU∶PVAL aqueous solution is 80∶20,the tensile strength of the composite is 116%higher than that of the blank film without dispersant,and the conductivity is 4.5×10^(-5)S/m,which is five grades higher than that of the blank film without dispersant.Scanning electron microscopy results show that graphene can be uniformly dispersed in the WPU matrix after adding PVAL aqueous solution,which indicates the PVAL aqueous solution has a good dispersion effect for graphene.