Alonso-Montemayor Francisco J, Espinach Francesc X, Tarrés Quim, Alcalà Manel, Delgado-Aguilar Marc, Mutjé Pere
LEPAMAP-PRODIS Research Group, University of Girona, C/Maria Aurèlia Capmany 61, 17003 Girona, Spain.
Polymers (Basel). 2023 Dec 21;16(1):37. doi: 10.3390/polym16010037.
Biocomposites from poly-(lactic acid) (PLA) and jute strands were prepared, and their flexural strength was analyzed. Jute strands were submitted to a progressive delignification process and the resulting morphology, composition, and crystallinity index were evaluated. Then, PLA biocomposites comprising 30 wt% of jute strands were produced and characterized under flexural conditions. The delignification processes decreased the lignin content and progressively increased the cellulose content. All this resulted in an enhancement of the composite flexural strength. A modified rule of mixtures, and the relation between tensile and flexural properties were used to determine the intrinsic flexural strength (of the jute strands) and their correlation with their physic-chemical characteristics. Equations correlating the intrinsic flexural strength with the crystallinity index, the cellulose content, and the microfibril angle were proposed. These equations show the impact of these properties over the intrinsic properties of the fibers and can help researchers to select appropriate fibers to obtain accurate properties for the composites. Jute strands show their value as reinforcement by increasing the flexural strength of the matrix by 70% and being less expensive and more environmentally friendly than mineral reinforcements. Together with the profitability and the environmental advantages, the mechanical results suggest that these PLA biocomposites are suitable for specific products of different market sectors.
制备了聚乳酸（PLA）与黄麻纤维的生物复合材料，并对其弯曲强度进行了分析。对黄麻纤维进行了逐步脱木素处理，并对所得的形态、组成和结晶度指数进行了评估。然后，制备了含有30 wt%黄麻纤维的PLA生物复合材料，并在弯曲条件下对其进行了表征。脱木素处理降低了木质素含量，并逐步提高了纤维素含量。所有这些都导致了复合材料弯曲强度的提高。使用修正的混合法则以及拉伸性能与弯曲性能之间的关系来确定（黄麻纤维的）固有弯曲强度及其与物理化学特性的相关性。提出了将固有弯曲强度与结晶度指数、纤维素含量和微纤丝角相关联的方程。这些方程显示了这些性能对纤维固有性能的影响，并可帮助研究人员选择合适的纤维，以获得复合材料的准确性能。黄麻纤维通过使基体的弯曲强度提高70%，并比矿物增强材料成本更低、更环保，从而显示出其作为增强材料的价值。结合经济效益和环境优势，力学结果表明这些PLA生物复合材料适用于不同市场领域的特定产品。
