The Quasi-static and Dynamic Mechanical Behavior of Epoxy Matrix Composites Reinforced with Curaua Fibers

The research of natural fiber composites is growing due to the fact that the green materials combine low weight with good mechanical properties. Curaua fiber arises as a competitive natural fiber due to its abundance, low cost and a variety of applications. In this work, different weight fractions of Curaua fiber were used in order to obtain this natural composite material. Specimens of Curaua/Epoxy composites were tested in tensile and in flexion to observe the quasi-static mechanical properties and its physical properties due to temperature variation were evaluated by Dynamic Mechanical Analyses (DMA) analyses. An increase in fiber quantity showed an increase in both the modulus and the strength, leading to a stiff and less ductile material. The results also showed an increase in the viscoelastic stiffness of the epoxy matrix by the incorporation of Curaua fibers. The interaction between Curaua fibers and epoxy matrix affects segmental mobility of the epoxy chains.

天然纤维复合材料的研究正得到快速发展，这类绿色材料兼具低密度与优异的力学性能。库劳纤维（Curaua fiber）凭借储量丰富、成本低廉且应用场景广泛的优势，成为极具竞争力的天然纤维材料。本研究通过调控库劳纤维的不同质量分数，制备了该天然复合材料。研究人员对库劳纤维/环氧树脂复合材料试样分别开展拉伸与弯曲测试，以表征其准静态力学性能；同时借助动态力学分析（Dynamic Mechanical Analyses, DMA），评估了温度变化对复合材料物理性能的影响。实验结果表明，纤维含量的提升可同时提高复合材料的模量与强度，使材料刚度提升、延展性降低。此外，掺入库劳纤维可有效增强环氧树脂基体的粘弹性刚度；库劳纤维与环氧树脂基体之间的界面相互作用，会影响环氧分子链的链段运动。