Janowski Grzegorz, Frącz Wiesław, Bąk Łukasz, Trzepieciński Tomasz
Department of Materials Forming and Processing, Rzeszow University of Technology, 35-959 Rzeszow, Poland.
Department of Manufacturing Processes and Production Engineering, Rzeszow University of Technology, 35-959 Rzeszow, Poland.
Polymers (Basel). 2022 Dec 8;14(24):5370. doi: 10.3390/polym14245370.
The paper presents a comparative analysis of two extrusion methods of biocomposites with a poly(3-hydroxybutyrate-co-3-hydroxyvalerate acid) (PHBV) matrix filled with flax and hemp fibers in terms of biopolymer production, its processing in the further injection process, and an evaluation of the mechanical and functional properties of the products. Biocomposites containing 15% by weight of the filler were produced using single- and twin-screw extruders. The biocomposites were then processed by injection molding and then, among other things, the pressures in the mold cavity during processing were analyzed. The produced samples were tested by means of the following tests: uniaxial tensile strength, hardness, and impact tensile strength. The biocomposite's microstructure was also analyzed using scanning electron microscopy (SEM), as were the shrinkage and water absorption of the manufactured products. In addition, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests were performed. It was found that the extrusion method changed significantly the geometry of the filler fibers and the processing capabilities of the manufactured materials. Significant differences in the mechanical and functional properties of the obtained biocomposite products were also found. On their basis, the advantages and disadvantages of both extrusion methods were discussed. Most of the obtained properties of injection products indicate the choice of single-screw extrusion. The products were characterized by slightly better mechanical properties and lower processing shrinkage. In turn, composites obtained by the screw method were characterized by lower water absorption and lower viscosity of the composite during injection molding.
本文对两种挤出方法制备的生物复合材料进行了对比分析，这两种生物复合材料以聚（3-羟基丁酸酯- co - 3-羟基戊酸酯）（PHBV）为基体，填充亚麻和大麻纤维，内容涉及生物聚合物的生产、其在后续注塑过程中的加工，以及对产品机械性能和功能特性的评估。使用单螺杆和双螺杆挤出机生产了含有15%（重量）填料的生物复合材料。然后通过注塑对生物复合材料进行加工，除此之外，还分析了加工过程中模腔内的压力。通过以下测试对生产的样品进行检测：单轴拉伸强度、硬度和冲击拉伸强度。还使用扫描电子显微镜（SEM）分析了生物复合材料的微观结构，以及制成产品的收缩率和吸水率。此外，还进行了热重分析（TGA）和差示扫描量热法（DSC）测试。结果发现，挤出方法显著改变了填料纤维的几何形状以及制成材料的加工性能。在所获得的生物复合材料产品的机械性能和功能特性方面也发现了显著差异。在此基础上，讨论了两种挤出方法的优缺点。注塑产品的大多数性能表明应选择单螺杆挤出。这些产品的特点是机械性能略好且加工收缩率较低。而通过双螺杆方法获得的复合材料的特点是吸水率较低且在注塑过程中复合材料的粘度较低。
