College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China.
College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China.
Int J Biol Macromol. 2022 Nov 30;221:773-783. doi: 10.1016/j.ijbiomac.2022.09.023. Epub 2022 Sep 9.
Polylactic acid-based (PLA) composites are widely used in biomedicine, electrical components, food packaging and other fields, but their unsatisfactory mechanical properties such as high brittleness and poor toughness, cause problems in functional applications. This work developed a green and environmentally friendly strategy to improve PLA mechanical properties. Flexible polybutylene succinate (PBS) and alkaline hydrogen peroxide (AHP) treated straw fibers (SF) synergistically modified PLA. AHP is decomposed into a large amount of HOO-, which oxidizes the hydroxyl groups in SF to carboxyl groups to obtain oxidized straw fiber (OSF), which reacts with PLA in the molten state to form new ester bonds. The tensile strength of the OSF/PLA composite is 41.78 MPa, 38 % higher than the SF/PLA composite. The impact toughness of OSF/PBS/PLA composite is 14.47 KJ/m increased by 54 % after the adding PBS, while the tensile strength was also better than the control group. The synergistic action of PLA and PBS in OSF is attributed to the formation of new chemical bonds, efficient crystallization, and compatible interface. This study provides a new strategy to produce fiber-reinforced PLA composites with good toughness. It takes positive significance for developing degradable plastics with good performance and controllable cost.
基于聚乳酸（PLA）的复合材料广泛应用于生物医学、电子元件、食品包装等领域，但由于其脆性高、韧性差等不尽如人意的力学性能，在功能应用中存在问题。本工作开发了一种绿色环保的策略来提高 PLA 的力学性能。柔性聚丁二酸丁二醇酯（PBS）和碱性过氧化氢（AHP）协同处理秸秆纤维（SF）来共同改性 PLA。AHP 分解产生大量的 HOO-，将 SF 中的羟基氧化为羧基，得到氧化秸秆纤维（OSF），OSF 在熔融状态下与 PLA 反应形成新的酯键。OSF/PLA 复合材料的拉伸强度为 41.78 MPa，比 SF/PLA 复合材料提高了 38%。添加 PBS 后，OSF/PBS/PLA 复合材料的冲击韧性提高了 54%，达到 14.47KJ/m，拉伸强度也优于对照组。OSF 中 PLA 和 PBS 的协同作用归因于新化学键的形成、高效结晶和相容界面。本研究为制备具有良好韧性的纤维增强 PLA 复合材料提供了一种新策略，对开发具有良好性能和可控成本的可降解塑料具有积极意义。
