In general, agricultural waste (residue) is left to nature or employed as fuel material in houses. However, such use of agricultural waste adversely affects the environment. To reduce the negative impact of agricultural waste on the environment, it can be utilized as natural filler in thermoplastic composites owing to its cellulosic structure. This research aims to determine ultraviolet (UV) and thermal ageing of natural fiber reinforced composites to investigate their potential of using in outdoor applications. Therefore, five kinds of agricultural waste were employed as natural fillers for fabricating polypropylene (PP) based composites in current research. Sunflower seed husk (dakota and white type), pumpkin seed husk, pistachio shell and hazelnut shell were utilized as natural fillers. Tensile behaviour of natural flour filled PP composites was characterized by a brittle failure. Though the natural fillers reduced the tensile and impact strength of pure PP, the mechanical properties were still acceptable for some applications and lower cost of natural filled PP composites made them feasible. It was concluded that sunflower seed husk (dakota and white type), pumpkin seed husk, pistachio shell and hazelnut shell flour filled PP composites could compete with pure PP when flexural strength was taken into consideration. Thus, more environmentally friendly composites with good flexural strength were developed. It was found that the influence of UV and thermal ageing on mechanical properties was not detrimental. In general, dakota type sunflower seed husk flour reinforcement gave the best mechanical properties among the natural composites, thus indicating better stress transfer.

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绿色复合材料的紫外线和热风化：比较不同农业废弃物作为填料的效果

一般来说，农业废物（残留物）被留给大自然或用作房屋的燃料材料。然而，农业废弃物的这种使用对环境产生不利影响。为了减少农业废物对环境的负面影响，由于其纤维素结构，它可以用作热塑性复合材料中的天然填料。本研究旨在确定天然纤维增强复合材料的紫外线 (UV) 和热老化，以研究它们在户外应用中的潜力。因此，在目前的研究中，五种农业废弃物被用作制造聚丙烯（PP）基复合材料的天然填料。向日葵籽壳（达科他和白色型）、南瓜籽壳、开心果壳和榛子壳被用作天然填料。天然面粉填充 PP 复合材料的拉伸行为以脆性破坏为特征。尽管天然填料降低了纯 PP 的拉伸和冲击强度，但其机械性能对于某些应用仍然是可以接受的，并且天然填充 PP 复合材料的较低成本使其成为可能。结果表明，考虑到抗弯强度，葵花籽壳（达科他和白色型）、南瓜籽壳、开心果壳和榛子壳粉填充的PP复合材料可以与纯PP竞争。因此，开发了具有良好弯曲强度的更环保的复合材料。结果表明，紫外线和热老化对机械性能的影响没有不利影响。一般来说，