Abstract

With increasing limitation of petrochemical resources, there is a growing demand for the replacement of nonrenewable fiber-reinforced polymer composites by renewable polymer composites. Therefore, the aim of this research work was to improve the mechanical properties of bast (plant) fibers reinforced polymer composites without reducing their renewable material content. To achieve this goal, basalt fibers (natural mineral fibers) were used to partially substitute the amount of bast fibers in the polymer composites. The applied fibers were processed to semi-finished materials by carding and needle punching and processed further by afterwards press-molding. An intense optimization of the carding process led to the production of homogeneous fabrics based on various types of fibers (bast, basalt and PP). The homogeneity of the fabrics was confirmed by scanning electron microscopy (SEM) analysis of the composites. Several composites based on polypropylene and acrylate thermoset resin, reinforced with merely bast fibers, were prepared as reference. In the next steps, the bast fiber content of the reference compositions was partially replaced by basalt fibers. The compression-molded samples were tested for their flexural, tensile, and impact energy properties. The very positive finding was that the addition of basalt fibers not just improved significantly the strength and stiffness of the composites, but simultaneously increased the properties of the composites regarding energy absorption, a key requirement in the automotive industry. The fracture surface analysis confirmed a better fiber matrix adhesion in thermoset composites compared to thermoplastic composites. The tested renewable hybrid polymer composites have great potential to replace nonrenewable fiber-reinforced polymer composites.

中文翻译：

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韧皮和玄武岩纤维增强聚合物复合材料的力学性能

摘要

随着石油化学资源的限制越来越大，用可再生的聚合物复合材料代替不可再生的纤维增强的聚合物复合材料的需求日益增长。因此，这项研究工作的目的是在不降低其可再生材料含量的情况下改善韧皮（植物）纤维增强聚合物复合材料的机械性能。为了实现这个目标，玄武岩纤维（天然矿物纤维）被用来部分替代聚合物复合物中韧皮纤维的数量。通过梳理和针刺将所施加的纤维加工成半成品，然后通过压模进一步加工。梳理工艺的高度优化导致了基于各种纤维（韧皮，玄武岩和PP）的均质织物的生产。织物的均匀性通过复合材料的扫描电子显微镜（SEM）分析得到证实。制备了几种仅用韧皮纤维增强的基于聚丙烯和丙烯酸酯热固性树脂的复合材料作为参考。在接下来的步骤中，参考组合物中韧皮纤维的含量被玄武岩纤维部分替代。测试压模样品的挠曲，拉伸和冲击能性能。非常积极的发现是，玄武岩纤维的添加不仅显着提高了复合材料的强度和刚度，而且同时提高了复合材料在能量吸收方面的性能，这是汽车工业的一项关键要求。断裂表面分析证实，与热塑性复合材料相比，热固性复合材料具有更好的纤维基质附着力。经过测试的可再生杂化聚合物复合材料具有巨大的潜力来替代不可再生的纤维增强聚合物复合材料。