Abstract

Aiming at reducing the environmental impact of low density polyethylene (LDPE) when employed as mulching film, this study was focused on the partial substitution of the material with proteins extracted from Hermetia illucens, also known as black soldier fly (BSF). Insects were reared on chicken manure and food leftovers in a circular economy perspective. To evaluate the effects of processing conditions and amount of BSF proteins on the properties of the final material the Design of Experiments technique was employed. Samples were obtained by hot mixing and compression molding, and their thickness, tensile stress, tensile strain, and Young modulus were measured and analyzed. According to mathematical models, the addition of BSF proteins in the mixture results in increased homogeneity and Young modulus of the material and in reduced tensile stress and strain. Results indicated that a LDPE-BSF proteins mixture of 50–50 wt%, processed at relative low temperature (130 °C) and time (3 min), ensures properties closer to pure molded LDPE (thickness = 0.8 mm, tensile stress = 6 MPa, tensile strain = 15% and Young modulus = 200 MPa) with lower environmental impact thanks to the high BSF proteins addition. Thereafter, BSF proteins can be employed as additive for LDPE for agricultural purposes, with processing methods feasible in an industrial perspective.

Graphical Abstract

中文翻译：

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从食品加工剩菜到生物塑料：循环经济视角下的实验方法设计

摘要

为了减少低密度聚乙烯 (LDPE) 用作地膜时对环境的影响，本研究的重点是用从Hermetia illucens 中提取的蛋白质部分替代该材料，也称为黑水虻（BSF）。从循环经济的角度来看，昆虫是用鸡粪和食物残渣饲养的。为了评估加工条件和 BSF 蛋白量对最终材料特性的影响，采用了实验设计技术。通过热混和压缩成型获得样品，并对其厚度、拉伸应力、拉伸应变和杨氏模量进行测量和分析。根据数学模型，在混合物中添加 BSF 蛋白质会增加材料的均匀性和杨氏模量，并降低拉伸应力和应变。结果表明，50–50 wt% 的 LDPE-BSF 蛋白质混合物，在相对较低的温度（130 °C）和时间（3 分钟）下加工，确保性能更接近于纯模制 LDPE（厚度 = 0.8 mm，拉伸应力 = 6 MPa，拉伸应变 = 15% 和杨氏模量 = 200 MPa），由于添加了高 BSF 蛋白质，对环境的影响较小。此后，BSF 蛋白质可用作农业用 LDPE 的添加剂，其加工方法在工业上是可行的。

图形概要