石墨烯多壁碳纳米管/超高分子量聚乙烯导电复合材料的制备及性能

为了比较超高分子量聚乙烯(UHMWPE)在单一填充和混合填充时, 复合材料导电性的差别。在超声和肼的作用下, 通过对氧化石墨烯(GO)、 多壁碳纳米管(MWCNTs)和超高分子量聚乙烯水/乙醇分散液减压蒸馏及热压制备了隔离型MWCNTs/UHMWPE、 石墨烯(GNS)/UHMWPE和MWCNTs-GNS/UHMWPE导电复合材料。经SEM、 TEM测试发现, 导电填料分散于UHMWPE颗粒表面, 热压后形成隔离结构。隔离型的MWCNTs/UHMWPE和GNS/UHMWPE复合材料均表现出较低的导电逾渗(0.148%和0.059%, 体积分数,下同), 但MWCNTs/UHMWPE复合材料的电导率(2.0×10^-2 S/m, 1.0%, 质量分数, 下同)明显高于相同填料含量下的GNS/UHMWPE复合材料。 MWCNTs-GNS/UHMWPE复合材料表现出了更低的逾渗(0.039%) 和较高导电性能(1.0×10^-2 S/m, 1.0%), 其拉伸强度和断裂伸长率随填充剂含量的增加呈现出先上升后下降的趋势。

Segregated ultrahigh molecular weight polyethylene composites filled with graphene sheets and hybrid multi-walled carbon nanotubes

For the sake of comparing the different electricity conductivities of composite materials when the UHMWPE filled singleness and mixed,graphene nanosheets(GNS)-multi-walled carbon nanotubes(MWCNTs)/ultrahigh molecular weight polyethylene(UHMWPE) composites with a segregated network structure were prepared by alcohol-assisted dispersion,ultrasound and hydrazine.SEM and TEM results show that MWCNTs or GNS homogeneously disperse around UHMWPE particle,and from a segregated conductive network during the hot-pressing.It is found that the percolation threshold of GNS/UHMWPE composites(0.059%,volume fraction)is much lower than that of MWCNTs/UHMWPE composites(0.148%,volume fraction).At the same filler content,the electrical conductivity of GNS/UHMWPE composites is much lower than that of the MWCNTs/UHMWPE composites(2.0×10-2 S/m,1.0%,mass fraction).The percolation threshold of GNS-MWCNTs/UHMWPE hybrid composites(0.039%,volume fraction) is lower than that of composites filled with GNS and MWCNTs alone,while the conductivity of GNS-MWCNTs/UHMWPE hybrid composites(1.0×10-2 S/m,1.0%,mass fraction) is similar to the MWCNTs/UHMWPE composites.The mechanical properties of composites increase and then decrease with the increasing content of fillers.