表面粗糙化玄武岩纤维的制备及其对PP基复合材料拉伸性能的影响

Preparation of Surface Roughened Basalt Fiber and Its Effect on Tensile Properties of Polypropylene Matrix Composites

玄武岩纤维(BF)具有耐化学腐蚀,耐热,高强高模,环境友好等独特优点,但其表面光滑且呈化学惰性,难以被聚合物润湿而发挥增强作用。采用硅烷偶联剂KH550和纳米二氧化硅(nano-SiO_(2))协同改性BF,并与聚丙烯(PP)熔融共混制备复合材料。综合利用傅立叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、示差扫描量热仪(DSC)和万能材料试验机对样品进行表征和测试,结果表明,nano-SiO_(2)可与KH550发生键合,并稳定沉积于BF表面,使BF表面粗糙化,从而增强了BF对PP熔体分子的润湿性,提升了BF与PP基体间的机械摩擦,促进了PP的异相成核,使PP结晶度从45.38%提升至53.40%,也使得BF与PP基体的界面结合更为紧密。最终,改性后的BF/PP复合材料的拉伸强度和弹性模量相比未改性样品可最高提升32.5%和28.5%,相比纯PP样品可最高提升42.2%和32.5%,增强效果良好。

Basalt fiber(BF)had unique advantages of chemical corrosion resistance, heat resistance, high strength, high modulus, environment-friendly and so on.However, its surface was smooth and chemically inert, so it was difficult to be wetted by polymer to play a reinforcing role.In this paper, BF was modified by silane coupling agent KH550 and nanosilicon dioxide(nano-SiO_(2)),and the composite was prepared by melt blending with polypropylene(PP).The samples were characterized and tested by Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM),differential scanning calorimeter(DSC)and universal material testing machine.The results show that nano-SiO_(2)can bond with KH550 and deposit on BF surface stably, which makes BF surface rough.This change enhances the wettability of BF to PP melt molecules, improves the mechanical friction between BF and PP matrix, and promotes heterogeneous nucleation of PP.As a result, the crystallinity of PP is increased from 45.38%to 53.40%,and the interface between BF and PP matrix becomes closer.Finally, the tensile strength and elastic modulus of the modified BF/PP composites can be increased by 32.5%and 28.5%,respectively, comparing with the unmodified samples, and up to 42.2%and 32.5%,respectively, comparing with the pure PP samples.