Although polymers based on polylactic acid (PLA) are considered by researchers as prime candidates for replacing traditional plastics, they are confronted with challenges including high production costs, limited thermal stability, and inferior impact resistance. In this study, novel composites with exceptional impact resistance, robust thermal stability, and satisfactory crystalline properties were fabricated by using PLA and polypropylene (PP) as raw materials, PP--MAH was employed as a compatibilizer to enhance the compatibility between the individual components. by adjusting the quantity of discarded cotton stalk fibers (CSF). The optimal mass ratio of CSF was determined to be 20%, resulting in a composite that exhibited a moderate increase of 56.31% in impact strength and a remarkable improvement of 23.05% in Vicat softening temperature. While the crystallinity was enhanced and the crystallization temperature (T) value decreased, the storage modulus also increased. Furthermore, the observed increase in storage modulus within the temperature range of 80 °C–100 °C was attributed to the influence of polymer cold crystallization. The hydrophobicity of the composite was enhanced. Significantly, this strategy can be extended to the application of other plant fibers, improving the crystalline properties of semi-crystalline polymers such as PLA and exemplifying the true ‘valorization of waste' through the secondary utilization of discarded CSF.

中文翻译：

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废棉秆与PP-g-mah增容剂增强聚乳酸/聚丙烯复合材料的冲击和结晶性能

尽管聚乳酸（PLA）聚合物被研究人员认为是替代传统塑料的主要候选材料，但它们面临着生产成本高、热稳定性有限和抗冲击性差等挑战。在这项研究中，以PLA和聚丙烯（PP）为原料，制备了具有优异的抗冲击性、强大的热稳定性和令人满意的结晶性能的新型复合材料，并采用PP--MAH作为增容剂来增强各个组分之间的相容性。通过调整废弃棉秆纤维（CSF）的数量。CSF的最佳质量比确定为20%，复合材料的冲击强度适度提高了56.31%，维卡软化温度显着提高了23.05%。在结晶度增强、结晶温度（T）值降低的同时，储能模量也增加。此外，在80°C-100°C的温度范围内观察到储能模量的增加归因于聚合物冷结晶的影响。复合材料的疏水性得到增强。值得注意的是，这一策略可以扩展到其他植物纤维的应用，改善PLA等半结晶聚合物的结晶性能，并通过废弃CSF的二次利用体现真正的“废物增值”。