This study aims to assess the mechanical properties of polymer composite (PC) reinforced by introducing two types of synthetic fibers including polypropylene (PP) and polyvinyl alcohol (PVA). The optimum amount of resin was evaluated through mechanical tests. Then, selected fibers were added to the optimum mix in three fractions (0.5%, 1%, and 1.5%) by the weight of the binder. Various properties of PC which are density, compressive strength, flexural strength, modulus of elastic, and water absorption were appraised for all mix combinations after different curing times (1, 3, 7, and 28 days) beside scanning electron microscopy analysis for microstructure observation. Experimental outcomes revealed that by rising the PP fiber content, the mechanical strengths of fiber‐reinforced polymer composite (FRPC) were ameliorated, where compressive and flexural strength grew 58.14% and 78.31%, respectively, at the highest fiber ratio (1.5%) compared with the plain PC. On the other hand, PC reinforced by PVA fibers represented an inverse behavior that by ascending the fiber fraction, reduction in the properties of FRPC observed. Therefore, the fiber content obtained better performance was 1.5% and 0.5% for PP and PVA mixtures in PC, respectively.

中文翻译：

---

聚丙烯和聚乙烯醇纤维对聚合物复合材料特性和微观结构的影响

这项研究旨在评估通过引入两种类型的合成纤维（包括聚丙烯（PP）和聚乙烯醇（PVA））增强的聚合物复合材料（PC）的机械性能。通过机械测试评估树脂的最佳用量。然后，将选定的纤维以粘合剂重量的三部分（0.5％，1％和1.5％）添加到最佳混合物中。在不同的固化时间（1、3、7、28天）之后，通过扫描电子显微镜分析对PC的各种特性（密度，抗压强度，弯曲强度，弹性模量和吸水率）进行评估，并进行扫描电子显微镜分析以观察微观结构。实验结果表明，通过提高PP纤维含量，可以改善纤维增强聚合物复合材料（FRPC）的机械强度，与普通PC相比，在最高纤维比率（1.5％）下，抗压强度和抗折强度分别增长了58.14％和78.31％。另一方面，由PVA纤维增强的PC表现出相反的行为，即通过提高纤维比例，降低FRPC的性能。因此，PC中的PP和PVA混合物获得的更好性能的纤维含量分别为1.5％和0.5％。