Sapiai Napisah, Jumahat Aidah, Jawaid Mohammad, Midani Mohamad, Khan Anish
Faculty of Mechanical Engineering, Universiti Teknologi MARA, Shah Alam, Selangor 40450, Malaysia.
Institute for Infrastructure Engineering Sustainable and Management, Universiti Teknologi MARA, Shah Alam, Selangor 40450, Malaysia.
Polymers (Basel). 2020 Nov 18;12(11):2733. doi: 10.3390/polym12112733.
This paper investigates the influence of silica nanoparticles on the mechanical properties of a unidirectional (UD) kenaf fiber reinforced polymer (KFRP) and hybrid woven glass/UD kenaf fiber reinforced polymer (GKFRP) composites. In this study, three different nanosilica loadings, i.e., 5, 13 and 25 wt %, and untreated kenaf fiber yarns were used. The untreated long kenaf fiber yarn was wound onto metal frames to produce UD kenaf dry mat layers. The silane-surface-treated nanosilica was initially dispersed into epoxy resin using a high-vacuum mechanical stirrer before being incorporated into the UD untreated kenaf and hybrid woven glass/UD kenaf fiber layers. Eight different composite systems were made, namely KFRP, 5 wt % nanosilica in UD kenaf fiber reinforced polymer composites (5NS-KFRP), 13% nanosilica in UD kenaf fiber reinforced polymer composites (13NS-KFRP), 25 wt % nanosilica in UD kenaf fiber reinforced polymer composites (25NS-KFRP), GKFRP, 5 wt % nanosilica in hybrid woven glass/UD kenaf fiber reinforced polymer composites (5NS-GKFRP), 13 wt % nanosilica in hybrid woven glass/UD kenaf fiber reinforced polymer composites (13NS-GKFRP) and 25 wt % nanosilica in hybrid woven glass/UD kenaf fiber reinforced polymer composites (25NS-GKFRP). All composite systems were tested in tension and bending in accordance with ASTM standards D3039 and D7264, respectively. Based on the results, it was found that the incorporation of homogeneously dispersed nanosilica significantly improved the tensile and flexural properties of KFRP and hybrid GKFRP composites even at the highest loading of 25 wt % nanosilica. Based on the scanning electron microscopy (SEM) examination of the fractured surfaces, it is suggested that the silane-treated nanosilica exhibits good interactions with epoxy and the kenaf and glass fibers. Therefore, the presence of nanosilica in an epoxy polymer contributes to a stiffer matrix that, effectively, enhances the capability of transferring a load to the fibers. Thus, this supports greater loads and improves the mechanical properties of the kenaf and hybrid composites.
本文研究了二氧化硅纳米颗粒对单向（UD）红麻纤维增强聚合物（KFRP）以及玻璃纤维/UD红麻纤维混杂编织增强聚合物（GKFRP）复合材料力学性能的影响。在本研究中，使用了三种不同的纳米二氧化硅含量，即5%、13%和25%（重量百分比），以及未处理的红麻纤维纱线。将未处理的长红麻纤维纱线缠绕在金属框架上，制成UD红麻干毡层。硅烷表面处理的纳米二氧化硅首先使用高真空机械搅拌器分散到环氧树脂中，然后再掺入UD未处理红麻纤维层以及玻璃纤维/UD红麻纤维混杂编织层中。制备了八种不同的复合体系，即KFRP、UD红麻纤维增强聚合物复合材料中含5%（重量百分比）纳米二氧化硅（5NS-KFRP）、UD红麻纤维增强聚合物复合材料中含13%（重量百分比）纳米二氧化硅（13NS-KFRP）、UD红麻纤维增强聚合物复合材料中含25%（重量百分比）纳米二氧化硅（25NS-KFRP）、GKFRP、玻璃纤维/UD红麻纤维混杂编织增强聚合物复合材料中含5%（重量百分比）纳米二氧化硅（5NS-GKFRP）、玻璃纤维/UD红麻纤维混杂编织增强聚合物复合材料中含13%（重量百分比）纳米二氧化硅（13NS-GKFRP）以及玻璃纤维/UD红麻纤维混杂编织增强聚合物复合材料中含25%（重量百分比）纳米二氧化硅（25NS-GKFRP）。所有复合体系分别按照ASTM标准D3039和D7264进行拉伸和弯曲测试。基于测试结果发现，即使在纳米二氧化硅含量高达25%（重量百分比）时，均匀分散的纳米二氧化硅的掺入也显著改善了KFRP和混杂GKFRP复合材料的拉伸和弯曲性能。基于对断裂表面的扫描电子显微镜（SEM）检查，表明硅烷处理的纳米二氧化硅与环氧树脂以及红麻和玻璃纤维表现出良好的相互作用。因此，环氧树脂聚合物中纳米二氧化硅的存在有助于形成更坚硬的基体，有效地增强了将载荷传递到纤维上的能力。从而，这有助于承受更大的载荷并改善红麻和混杂复合材料的力学性能。
