This study evaluates the water diffusion mechanism on mechanical properties of polypropylene reinforced composites. Compounding of the composites into sheets was carried out using the compression moulding techniques by incorporating varying weight percentage of fibers and polypropylene. Mechanical properties of the composites were assessed according to ASTM standards, while the composite fracture surface was examined using a scanning electron microscope. The water absorption behaviour and diffusion mechanisms on mechanical properties of fabricated composites were analysed using a water immersion test and the Fickian diffusion model. The results show that mechanical properties of all polypropylene reinforced composites under dry condition was higher than wet condition. The composites reinforced with 7 wt.% (KOH and NaOH) fibers follow a consistent trend and gave the highest tensile strength and tensile modulus in comparison with pure PP (polypropylene). Addition of fibers into the polypropylene matrix gradually decreases composites impact strength with exception to 3 wt.% and 5 wt.% composites. The hardness properties of reinforced composites were steadily increased as the fiber loading increases which signify strong fiber-matrix bonding. The percentage of water absorbed for all reinforced composites increased as the fiber weight increases and slowly flattened off after 10 days of saturation. The morphological study revealed fiber pullout and delamination of reinforced composites attributed to poor fiber-matrix adhesion amount to water intake. The diffusion transport mechanism of polypropylene composites was observed to obey the Fickian diffusion model.

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水扩散机理对聚丙烯复合材料力学性能的评价

本研究评估了水扩散机理对聚丙烯增强复合材料力学性能的影响。使用压缩成型技术，通过掺入不同重量百分比的纤维和聚丙烯，将复合材料复合成片。根据ASTM标准评估复合材料的机械性能，同时使用扫描电子显微镜检查复合材料的断裂表面。使用水浸试验和菲克扩散模型分析了复合材料的吸水行为和扩散机理对复合材料力学性能的影响。结果表明，所有聚丙烯增强复合材料在干态下的力学性能均高于湿态。用7wt。％增强的复合材料。％（KOH和NaOH）纤维遵循一致的趋势，并且与纯PP（聚丙烯）相比具有最高的拉伸强度和拉伸模量。除了3wt。％和5wt。％的复合材料外，将纤维添加到聚丙烯基质中逐渐降低了复合材料的冲击强度。随着纤维含量的增加，增强复合材料的硬度性能稳步提高，这表明纤维与基质之间的牢固结合。所有增强复合材料的吸水百分比随着纤维重量的增加而增加，并在饱和10天后逐渐变平。形态学研究表明，增强复合材料的纤维拔出和分层是由于纤维基质对取水量的附着力差所致。