Abstract Polypropylene composites were prepared from neat and alkali-treated sugarcane bagasse fibers. The results showed that alkali treatment leads to an increase in composite stiffness and strength. A maximum is achieved in these properties at around 5 wt% NaOH content of the treating solution. The increase in properties was assigned to the improvement in inherent fiber characteristics. Acoustic emission testing and electron microscopy showed that the two main local deformation processes related to the fibers are their fracture and debonding; the latter is accompanied by the shear yielding of the matrix. Increased inherent strength of the fibers results in an increase in the fracture initiation stress and fracture energy of the composites. Interfacial adhesion has a slight effect on stiffness, but more significant on strength and impact resistance. Changing adhesion modifies the relative importance of local deformation processes, the number of debonding events decreases, while fiber fracture increases with increasing adhesion. Increased interfacial adhesion improves stress transfer and the load bearing capacity of the fibers as well, but suppresses matrix yielding. Alkali treatment increases inherent fiber strength, which can be directly correlated with composite strength.

中文翻译：

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用碱处理过的甘蔗渣纤维增强聚丙烯：机理和后果

摘要 聚丙烯复合材料由纯碱处理的甘蔗渣纤维制备而成。结果表明，碱处理导致复合材料刚度和强度的增加。在处理溶液的 NaOH 含量约为 5%（重量）时，这些性能达到最大值。性能的增加归因于固有纤维特性的改进。声发射测试和电子显微镜表明，与纤维相关的两个主要局部变形过程是断裂和脱粘；后者伴随着基体的剪切屈服。纤维固有强度的增加导致复合材料的断裂起始应力和断裂能的增加。界面附着力对刚度有轻微影响，但在强度和抗冲击性上更显着。改变附着力会改变局部变形过程的相对重要性，脱粘事件的数量减少，而纤维断裂随着附着力的增加而增加。增加的界面粘合也改善了应力传递和纤维的承载能力，但抑制了基体屈服。碱处理增加了固有纤维强度，这可以与复合材料强度直接相关。