Pinheiro Miriane Alexandrino, Galvao Neto Leoncio Soares, da Silva Alisson Clay Rios, Monteiro Sérgio Neves, Lopes Felipe Perisse Duarte, Dos Reis Marcos Allan Leite, Candido Verônica Scarpini
Engineering of Natural Resources of the Amazon Program, Federal University of Pará, Ananindeua 67030-007, PA, Brazil.
Materials Science and Engineering Program, Federal University of Pará, Ananindeua 67030-007, PA, Brazil.
Polymers (Basel). 2025 Aug 23;17(17):2284. doi: 10.3390/polym17172284.
Natural lignocellulosic fibers (NLFs) replacing synthetic fibers have been used as reinforcement in polymer matrix composites. In this work, a lesser-known NLF endemic to the Amazon region, the envira fiber (), was analyzed for its basic physical, thermochemical, morphological, and mechanical characteristics. In addition, epoxy matrix composites with 10, 20, 30, and 40 vol% of continuous and aligned envira fibers were evaluated by Fourier transform infrared spectroscopy (FTIR) and tensile tests. The results were statistically compared by ANOVA and Tukey's test. The density found for the envira fiber was 0.23 g/cm. The crystallinity index and microfibrilar angle obtained were 69.5% and 7.07°, respectively. Fiber thermal stability was found up to around 210 °C. FTIR confirmed the presence of functional groups characteristic of NLFs. Morphological analysis by SEM revealed that the envira fiber displayed fine bundles of fibrils and a rough surface along its length. The average strength value of the envira fiber was found to be 62 MPa. FTIR analysis of the composites confirmed the presence of the main constituents of the epoxy resin and NLFs. The tensile strength results indicated that the envira fiber addition increased the strength of the composites up to 40 vol%. The analysis of the fracture region revealed brittle aspects. These results indicate that envira fibers present potential reinforcement for polymer matrix composites and can be used in engineering applications, favored by their lightness and cost-effectiveness.
天然木质纤维素纤维（NLFs）替代合成纤维已被用作聚合物基复合材料的增强材料。在这项工作中，对一种亚马逊地区特有的鲜为人知的NLF——恩维拉纤维（）的基本物理、热化学、形态和力学特性进行了分析。此外，通过傅里叶变换红外光谱（FTIR）和拉伸试验对含有10%、20%、30%和40%体积分数连续且排列整齐的恩维拉纤维的环氧基复合材料进行了评估。通过方差分析（ANOVA）和Tukey检验对结果进行了统计学比较。测得的恩维拉纤维密度为0.23 g/cm³。得到的结晶度指数和微纤丝角分别为69.5%和7.07°。发现纤维热稳定性可达约210℃。FTIR证实了NLFs特征官能团的存在。扫描电子显微镜（SEM）的形态分析表明，恩维拉纤维沿其长度呈现出细小的原纤维束和粗糙的表面。发现恩维拉纤维的平均强度值为62 MPa。对复合材料的FTIR分析证实了环氧树脂和NLFs主要成分的存在。拉伸强度结果表明，添加恩维拉纤维使复合材料的强度提高到40%体积分数。对断裂区域的分析揭示了脆性特征。这些结果表明，恩维拉纤维对聚合物基复合材料具有潜在的增强作用，因其轻质和成本效益高而可用于工程应用。
