Andrzejewski Jacek, Nowakowski Michał
Polymer Processing Division, Institute of Materials Technology, Faculty of Mechanical Engineering, Poznan University of Technology, ul. Piotrowo 3, 61-138 Poznan, Poland.
MATRIX Students Club, Polymer Processing Division, Poznan University of Technology, ul. Piotrowo 3, 61-138 Poznan, Poland.
Materials (Basel). 2021 Mar 20;14(6):1523. doi: 10.3390/ma14061523.
The presented study focuses on the development of flax fiber (FF) reinforced composites prepared with the use of poly(lactic acid)/poly(butylene adipate-co-terephthalate)-PLA/PBAT blend system. This type of modification was aimed to increase impact properties of PLA-based composites, which are usually characterized by high brittleness. The PLA/PBAT blends preparation was carried out using melt blending technique, while part of the samples was prepared by reactive extrusion process with the addition of chain extender (CE) in the form of epoxy-functionalized oligomer. The properties of unreinforced blends was evaluated using injection molded samples. The composite samples were prepared by compression molding technique, while flax fibers reinforcement was in the form of plain fabric. The properties of the laminated sheets were investigated during mechanical test measurements (tensile, flexural, impact). Differential scanning calorimetry (DSC) analysis was used to determine the thermal properties, while dynamic mechanical thermal analysis (DMTA) and heat deflection temperature (HDT) measurements were conducted in order to measure the thermomechanical properties. Research procedure was supplemented with structure evaluation using scanning electron microscopy (SEM) analysis. The comparative study reveals that the properties of PLA/PBAT-based composites were more favorable, especially in the context of impact resistance improvement. However, for CE modified samples also the modulus and strength was improved. Structural observations after the impact tests confirmed the presence of the plastic deformation of PLA/PBAT matrix, which confirmed the favorable properties of the developed materials. The use of PBAT phase as the impact modifier strongly reduced the PLA brittleness, while the reactive extrusion process improves the fiber-matrix interactions leading to higher stiffness and strength.
本研究聚焦于使用聚乳酸/聚（己二酸丁二醇酯-对苯二甲酸丁二醇酯）（PLA/PBAT）共混体系制备亚麻纤维（FF）增强复合材料。这种改性旨在提高通常具有高脆性的聚乳酸基复合材料的冲击性能。PLA/PBAT共混物采用熔融共混技术制备，而部分样品通过反应挤出工艺制备，并添加环氧官能化低聚物形式的扩链剂（CE）。未增强共混物的性能通过注塑样品进行评估。复合样品采用压缩成型技术制备，亚麻纤维增强材料为平纹织物形式。在机械性能测试（拉伸、弯曲、冲击）过程中研究层压板的性能。采用差示扫描量热法（DSC）分析来确定热性能，同时进行动态机械热分析（DMTA）和热变形温度（HDT）测量以测量热机械性能。研究过程还通过扫描电子显微镜（SEM）分析进行结构评估。对比研究表明，基于PLA/PBAT的复合材料性能更优，尤其是在提高抗冲击性方面。然而，对于CE改性样品，模量和强度也有所提高。冲击试验后的结构观察证实了PLA/PBAT基体存在塑性变形，这证实了所开发材料的良好性能。使用PBAT相作为抗冲改性剂极大地降低了聚乳酸的脆性，而反应挤出工艺改善了纤维与基体的相互作用，从而提高了刚度和强度。
