Fabrication of Manila Hemp Fiber Reinforced Cross Ply Biodegradable Composites and Their Tensile Properties

Natural plant fibers, including flax, kenaf, jute, bamboo, ramie and much more are renewable and sustainable resources and are considered good candidates for cost-effective alternatives to glass and carbon fibers. In this research, cross ply biodegradable composites were fabricated by press-forming method. The biodegradable composites consist of Manila hemp textile as a reinforcement and starch-based biodegradable plastics as a matrix was fabricated and investigated about mechanical properties. The tensile strength increased with the fiber content until fiber content of about 50% and leveled off thereafter. This dependence on the fiber content is due to the decrease in fiber strength of loading direction caused by fiber damages introduced during hot-pressing. In order to decrease the damage of fibers aligned in loading direction, Manila hemp textile was produced by using Manila hemp fibers for warp and biodegradable resin thread for weft. As a result, the tensile strength of cross ply composites increased from 153 MPa to 202 MPa.

碱处理对马尼拉麻纤维结构及纸质振膜电声性能的影响

纸质振膜的力学性能会影响扬声器的电声(频率响应)特性,通过对天然纤维改性处理能改善振膜的力学性能。讨论了碱液浓度和处理时间对马尼拉麻纤维结构及纸质振膜力学性能和电声性能的影响。采用SEM、XRD、FT-IR、TGA等表征方法对碱处理前后的马尼拉麻纤维表面形貌、结晶结构、化学组分等进行测试分析。结果表明,随着碱液浓度或处理时间的增加,纤维表面粗糙度增大、纤维的结晶度先增大后减小、纤维表面的木质素及半纤维素减少、纤维素热稳定性提高,木质素的热稳定性降低。碱液浓度过大或处理时间过长,均会导致纤维素的降解,影响振膜力学强度。碱液浓度为5%(质量分数)、室温处理3h时,纤维振膜的力学性能和电声性能达到最佳。