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日益受到重视，这类绿色材料兼具轻质特性与优异力学性能。库劳阿纤维（Curaua fiber）凭借其储量充沛、成本低廉且应用场景广泛的特点，成为极具竞争力的天然纤维备选材料。本研究通过调整库劳阿纤维的质量分数，制备了系列库劳阿纤维/环氧树脂复合材料试样。针对该类试样开展拉伸与弯曲试验，以表征其准静态力学性能；同时采用动态力学分析（Dynamic Mechanical Analyses, DMA）测试试样随温度变化的物理特性。研究结果表明，纤维掺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、塑性降低。此外，掺入库劳阿纤维可增强环氧树脂基体的粘弹性刚度，纤维与环氧树脂基体之间的界面相互作用会影响环氧树脂分子链的段运动能力。