三聚氰胺氰脲酸盐复合尼龙6的形效关系

摘要

Three kinds of MCA with stick-like,sphere-like and slice-like morphologies were blended with PA6 to prepare MCA/PA6 composites respectively.The physical-mechanical properties of PA6 composites were characterized by using scanning electron microscopy,differential scanning calorimeter,electromechanical universal testing machine,Izod notched impact tester and melt flow rate tester.The results showed that different morphologies of MCA had various influences on the properties of MCA/PA6 composites.The nano-slice-like MCA particle (MCA-C) (content was 8％) had the most outstanding effect on the physical-mechanical properties of composites.Namely,in contrast with that of pure PA6,the stretch strength,break stress strength,impact strength of MCA-C/PA6 composite increased by 8％,29％ and 23％ respectively.The enhancement of stretch strength was caused by the more hydrogen bonds between nano-slicelike MCA and PA6 ; the increase of impact strength was the reason that the PA6 in composites can deform and produce craze in the interface to absorb the impact energy when the composites receive external impact.Moreover,the morphology of MCA-C and the hydrogen bonds interaction also reduced the melt index of MCAC/PA6 composite by 39％ and the crystallization temperature also increased from 169 ℃ to 192 ℃ due to the heterogeneous nucleation compared with virgin PA6.%具有棒状、近球状和片状三种形态的三聚氰胺氰脲酸盐(MCA)分别与尼龙6共混制备成MCA/尼龙6复合材料,并通过扫描电子显微镜、示差扫描量热仪、电子万能试验机、悬臂梁冲击试验机、熔体质量流动速率仪对其物理机械性能进行了表征.结果表明,不同形态的MCA对复合材料的各项性能具有明显不同的影响,其中纳米片状粒子(MCA-C)对复合材料的性能影响最为明显,当MCA-C的质量分数达到8％时,复合尼龙6的拉伸强度较纯样品提高了8％,拉伸断裂应力提高了29％,冲击强度提升了23％.其中拉伸强度的提高是由于纳米片状MCA粒子与尼龙6形成了更多的分子间氢键相互作用;而冲击强度的提高可能是由于当复合材料受到外力冲击时,材料中的尼龙6发生弹性形变并在与MCA的界面处产生银纹而吸收冲击能量,从而提高了冲击强度.此外,由于MCA与基体的氢键作用及其颗粒形状的影响,与纯尼龙6相比,MCA-C/尼龙6复合材料的熔体质量流动速率也降低了39％,而异相成核作用导致复合材料的结晶温度由169℃升高至192℃.