This research focuses on the development of an environmentally friendly composite directly from recycled high density polyethylene (rHDPE) grocery bags without changing their film form. Untreated and alkali-treated hemp fibers are used as reinforcement for a composite with recycled High Density Polyethylene (rHDPE) and a combination of rHDPE and virgin HDPE (vHDPE). Grocery bags and hemp fibers are characterized using Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). Fiber preforms are produced using a hydro-entanglement method and compression molded with HDPE and/or rHDPE at weight fractions of 30, 40, and 50%. The hemp fiber HDPE composites are characterized and tested for their tension and flexure performance. The results show an improvement in mechanical properties when using treated fibers as well as the addition of vHDPE to the polymer matrix. The highest tensile and flexural strength values for the pure rHDPE composite were acquired after adding 40 and 50% weight fraction of treated fibers, respectively. An increase of around 10 MPa on both of these properties was found when using the optimized combination of the recycled and virgin matrix materials with 40 and 50% weight fraction of reinforcement, respectively. It is concluded that the composite made of hemp fibers and recycled plastic bag has relatively good mechanical properties and can be potentially used for secondary structural use.

中文翻译：

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用回收的高密度聚乙烯食品袋开发大麻纤维复合材料

这项研究的重点是直接从回收的高密度聚乙烯 (rHDPE) 食品袋中开发一种环保复合材料，而不改变其薄膜形式。未经处理和碱处理的大麻纤维用作具有回收高密度聚乙烯 (rHDPE) 以及 rHDPE 和原始 HDPE (vHDPE) 组合的复合材料的增强材料。食品袋和大麻纤维使用傅里叶变换红外光谱 (FTIR)、差示扫描量热法 (DSC) 和热重分析 (TGA) 进行表征。纤维预制件使用水刺法生产，并使用重量分数为 30%、40% 和 50% 的 HDPE 和/或 rHDPE 进行压缩成型。对大麻纤维 HDPE 复合材料进行了表征并对其拉伸和弯曲性能进行了测试。结果表明，当使用处理过的纤维以及将 vHDPE 添加到聚合物基体时，机械性能有所改善。在分别添加 40% 和 50% 重量分数的处理过的纤维后，获得了纯 rHDPE 复合材料的最高拉伸和弯曲强度值。当使用分别具有 40% 和 50% 增强材料重量分数的回收和原始基体材料的优化组合时，发现这两种性能均增加了约 10 MPa。结论是由大麻纤维和再生塑料袋制成的复合材料具有较好的机械性能，可用于二次结构用途。在分别添加 40% 和 50% 重量分数的处理过的纤维后，获得了纯 rHDPE 复合材料的最高拉伸和弯曲强度值。当使用分别具有 40% 和 50% 增强材料重量分数的回收和原始基体材料的优化组合时，发现这两种性能均增加了约 10 MPa。结论是由大麻纤维和再生塑料袋制成的复合材料具有较好的机械性能，可用于二次结构用途。在分别添加 40% 和 50% 重量分数的处理过的纤维后，获得了纯 rHDPE 复合材料的最高拉伸和弯曲强度值。当使用分别具有 40% 和 50% 增强材料重量分数的回收和原始基体材料的优化组合时，发现这两种性能均增加了约 10 MPa。结论是由大麻纤维和再生塑料袋制成的复合材料具有较好的机械性能，可用于二次结构用途。