纳米石墨微片/聚氯乙烯复合材料的制备与性能

利用超声作用制备纳米石墨微片(nano-Gs), 并采用混酸对其进行表面活化, 最后通过熔融共混法制备nano-Gs/聚氯乙烯(PVC)复合材料。通过FTIR、 SEM对nano-Gs的结构进行表征, 并研究了nano-Gs对nano-Gs/PVC复合材料导电性能和力学性能的影响。FTIR分析表明: nano-Gs经混酸处理后表面活性官能团含量明显升高, 并与PVC 分子链发生一定程度的氢键作用; SEM图片显示: nano-Gs 厚度为30～80 nm, 其微片宽度为4～20 μm, 在PVC 树脂基体中呈无规状均匀分布; 导电性能测试表明: 随着nano-Gs 含量升高, nano-Gs/PVC复合材料的体积电阻率呈非线性降低趋势, 最低为103 Ω·cm, nano-Gs 的逾渗阈值为10%(质量分数); 力学性能测试表明, 随着nano-Gs含量升高, nano-Gs/PVC复合材料的拉伸强度及缺口冲击强度均先升高后降低, nano-Gs质量分数为1%时, 复合材料的拉伸强度及缺口冲击强度均达到最大值, 相比纯PVC分别升高约14%和38%。 

Fabrication and properties of graphite nanosheets/poly composites

Graphite nanosheets (nano-Gs) were prepared via sonication and then activated with mixed acid, finally the nano-Gs/PVC composites were prepared by way of melt blending. The structure of nano-Gs was characterized by FTIR and SEM, and the impact of nano-Gs on the conductive and mechanical properties of nano-Gs/PVC composites was also studied. The FTIR spectra demonstrate that the surface-active functional groups of nano-Gs increase significantly after mixed acid treatment, which form a certain degree of hydrogen bonding with PVC molecular chains. The SEM micrographs show that nano-Gs have a thickness ranging 30-80 nm and a diameter ranging 4-20 μm, and disperse randomly in PVC resin matrix. The electrical performance testing indicates that with the increase of the filled nano-Gs, the volume resistivity of the nano-Gs/PVC composites decreases nonlinearly and reachs the lowest value of 103Ω·cm when the mass fraction of nano-Gs reachs its percolation threshold (10%). The mechanics performance testing shows that with the increase of the filled nano-Gs, both the tensile strength and notched impact strength of the composites increase first and then decrease, when the mass fraction of nano-Gs is 1%, the tensile strength and notched impact strength achieve the maximal value simultaneously and increase by 14% and 38% respectively compared with the pure PVC.