Wheat flour thermoplastic matrix reinforced by waste cotton fibre: Agro-green-composites

New composites materials, 100% ecofriendly, having waste cotton fibre as reinforcement in wheat flour based thermoplastic matrix were prepared by extrusion method. The fibre content in the composite varied from 0 to 15% w/w. Using X-ray diffraction and scanning electron microscopy, the structure and morphology of the composites have been analysed. This investigation is focused on the effects of the fibre content on the mechanical and thermal properties of the composites. Addition of the waste cotton fibre to the matrix increased the tensile properties. For the composite with 10% w/w of fibre the values of the tensile stress are found maximum. We also show that thermal conductivity and resistivity are not affected by the fibre content. By thermogravimetry we show that the addition of fibres to the matrix has no significant influence on the thermal stability of the composites. Finally, to analyse the efficiency of the present system, a comparative study of the mechanical properties obtained with flax and cotton fibres is performed.     

三类典型一次性外卖餐盒的全生命周期评价

基于食品加工安全和生态环境防治,该文采用生命周期评价(LCA)方法对以聚丙烯(PP)、聚乳酸(PLA)和热塑性淀粉(TPS)为原料的一次性外卖餐盒进行环境影响指标评估,并比较原料获取阶段(摇篮到门)、制品生产阶段(门到门)、废弃物处理阶段(门到坟墓)的碳排放当量和能源消耗参数。以1000个一次性外卖餐盒为基准流,利用环境评估软件建立了一次性塑料餐盒从摇篮到坟墓全生命周期评估模型。其中,三类典型塑料餐盒的碳排放当量在原材料获取和废弃物处理阶段最大,而资源和能源消耗则主要发生在原材料获取和产品生产阶段。TPS餐盒累计释放98.84 kg CO₂,消耗679.02 MJ能源,与PP和PLA餐盒相比碳排放低46.90%、28.30%,节省能源4270.94 MJ、615.2 MJ。因此在餐饮外卖领域推广使用TPS替代制品可有效治理一次性塑料餐盒环境污染。