多壁碳纳米管-有机蒙脱土协同增韧环氧树脂

Synergistic effect of multi-wall carbon nanotube and organophilic montmorillonite on toughening epoxy resin

采用机械搅拌和离心分散的方法制备了多壁碳纳米管-有机蒙脱土/环氧树脂复合材料。X射线衍射分析表明,当有机蒙脱土含量为2 wt%时,蒙脱土在树脂体系中能够形成离散性结构。断裂韧性测试结果表明,多壁碳纳米管和有机蒙脱土的混杂对环氧树脂具有协同增韧的作用。当有机蒙脱土含量为2 wt%,多壁碳纳米管含量为0.1 wt%时,所得复合材料的断裂韧性是纯环氧树脂的1.77倍,是2 wt%有机蒙脱土/环氧树脂复合材料的1.45倍,是0.1 wt%多壁碳纳米管/环氧树脂复合材料的1.39倍。扫描电镜分析表明,多壁碳纳米管在环氧树脂体系中分散均匀,并与有机蒙脱土片层形成了一定程度的相互穿插和咬合,多壁碳纳米管与有机蒙脱土协同增韧的主要原因是微裂纹增韧、剪切屈服与纤维拔出。

Epoxy resin matrix composites with various contents of multi-wall carbon nanotubes（MWCNTs） and organophilic montmorillonite（oMMT） were prepared by means of shearing mixing and speed mixture. X- ray diffraction analysis shows that the exfoliated microstructure is formed when the mass fraction of oMMT was 2~. The fracture tests indicate that MWCNTs and oMMT exhibit synergistic effect on improving the critical stress intensity factor of the pure epoxy. When incorporating 2 wt% oMMT and 0.1 wt% MWCNTs into the epoxy resin at the same time, the fracture toughness of the composite is 1.77, 1.45 and 1.39 times that of pure epoxy, 2 wt% oMMT/epoxy and 0. 1 wt% MWCNTs/epoxy composite, respectively. The scanning electronic microscope observations show that MWCNTs are dispersed well in the matrix and a certain degree of platelet interlocks structure is achieved. The fracture surface micrographs prove that micro-cracks, cavities and fiber pull-out are responsible for improving the toughness of MWCNTs-oMMT/epoxy resin composites.