ABSTRACT

To investigate the feasibility of preparing biodegradable composites as food packing materials from reed leaf fibers to substitute disposable plastic, the fibers were treated by hot water (HWT), Na₂CO₃ solution (NCT) and ultrasound (UST), respectively and then combined with agar to prepare biodegradable composites through compression molding technique. The effects on the morphology, thermal properties of reed leaf fibers and the tensile cross-section morphology, the mechanical properties, the thermal conductivity and the moisture absorption profiles of the composites were studied. The amorphous components such as lignin and hemicellulose in reed leaf fibers were removed after HWT, NCT and UST. The fibers had a rough surface after hot water treatment which can lead to a better combination with agar induce an obvious improvement on the mechanical properties of the composites. The tensile strength, flexural strength and the impact strength of the HWT composite were 3.37 MPa, 19.7 MPa and 14.01 MPa, higher than that of the untreated (UT) composite and 22.99%, 16.36% and 69%, respectively. The HWT composite had a better hydrophobicity which equilibrium moisture absorption rate was 32.12%. The thermal conductivity of all the composites were less than 0.23 W·m⁻¹·k⁻¹, which were thermal insulating.

摘要

为了研究用芦苇叶纤维制备可生物降解复合材料作为食品包装材料以替代一次性塑料的可行性，将纤维用热水 (HWT)、Na ₂ CO _{3 处理}溶液（NCT）和超声（UST），然后与琼脂结合，通过压缩成型技术制备可生物降解的复合材料。研究了芦苇叶纤维的形貌、热性能和拉伸截面形貌、力学性能、热导率和吸湿性对复合材料的影响。芦苇叶纤维中的木质素和半纤维素等无定形成分在HWT、NCT和UST后被去除。纤维经过热水处理后表面粗糙，可以与琼脂更好地结合，从而显着提高复合材料的力学性能。HWT复合材料的拉伸强度、弯曲强度和冲击强度分别为3.37 MPa、19.7 MPa和14.01 MPa，分别高于未处理 (UT) 复合材料和 22.99%、16.36% 和 69%。HWT复合材料具有较好的疏水性，平衡吸湿率为32.12%。所有复合材料的导热系数均小于0.23 W·m^-1 ·k ^-1，它们是绝热的。