In order to improve interfacial adhesion between poly(lactic acid) (PLA) and sisal fibers (SFs), bifunctional monomer bisoxazoline (BO) was introduced into melt‐blending process of fibers reinforced PLA composites via in situ reactive interfacial compatibilization. The morphology of fibers and their reinforced PLA composites, thermal, and mechanical properties of the composites were studied. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) results confirmed that PLA was successfully grafted onto the surface of fiber. BO played a hinge‐like role between PLA molecular chains and SFs. The interfacial reaction and the microstructures of the SF‐reinforced PLA composites were investigated by thermal analysis. The cold crystallization temperature of the composites increased by 6.5°C with the addition of 0.6 wt% BO and 20 wt% SF as compared with the composites without BO. Microdebonding test further confirmed that interfacial shear strength of samples with BO increased by more than 30.7% in comparison with unmodified samples. For composites with 20 wt% SF addition, tensile strength and modulus increased by 34% and 10%, respectively, with 1 wt% BO addition. Flexural strength and modulus increased by 25% and 8%, respectively, with the addition of 1.2 wt% BO. Impact strength of 1 wt% BO‐modified composites was 5.1 MPa, which is 17% higher than that of the composites without BO.

中文翻译：

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添加双恶唑啉可提高剑麻纤维增强聚乳酸复合材料的界面粘合性和力学性能

为了提高聚乳酸（PLA）和剑麻纤维（SFs）之间的界面粘合性，将双功能单体双恶唑啉（BO）通过原位引入到纤维增强的PLA复合材料的熔融共混过程中反应性界面相容性。研究了纤维及其增强的PLA复合材料的形貌，复合材料的热性能和机械性能。傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）的结果证实，PLA已成功接枝到纤维表面。BO在PLA分子链和SF之间起到了类似铰链的作用。通过热分析研究了SF增强的PLA复合材料的界面反应和微观结构。与不含BO的复合材料相比，在添加0.6wt％的BO和20wt％的SF的情况下，复合材料的冷结晶温度提高了6.5℃。微脱粘试验进一步证实，与未改性的样品相比，含BO的样品的界面剪切强度提高了30.7％以上。对于添加20 wt％SF的复合材料，添加1 wt％BO时的拉伸强度和模量分别增加了34％和10％。加入1.2 wt％的BO，弯曲强度和模量分别增加了25％和8％。1 wt％BO改性的复合材料的冲击强度为5.1 MPa，比不含BO的复合材料高17％。