Purpose While bio-based composites (bio-based plastics reinforced with natural fibers) have been discussed as potential sustainable alternatives to petroleum-based plastic composites, there are few quantitative environmental impact assessments of these materials. This work presents comparisons of petroleum-based and bio-based plastics as well as their composites to (1) assess environmental impacts from plastics and composite production and (2) determine which environmental impacts can be mitigated through production of bio-based composites, based on current manufacturing methods. Methods Environmental impact assessments were performed to determine the burdens associated with cradle-to-gate production of bio-based and petroleum-based plastics and their composites with wood flour (i.e., sawdust) filler. The scope of this work incorporated emissions from thermoplastic and wood flour production as well as pelletization, molding, and transportation processes. Environmental impacts were assessed for several impact categories using the US Environmental Protection Agency’s TRACI method. Using impacts quantified, as well as material property data from 36 sources in the literature, comparisons were drawn between composite types. Multiple functional units were used including a constant mass of material produced and two comparison methods normalizing environmental impacts by material properties. Uncertainty assessments were performed to determine environmental impact distributions for each plastic and wood fiber composite type. Results and discussion The production of bio-based plastics and their composites led to lower environmental impacts than petroleum-based plastics and composites in several impact categories: global warming potential, fossil fuel depletion, and certain human health impacts. However, the production of bio-based plastics and their composites also resulted in some higher environmental impacts, such as eutrophication. Bio-based composites are capable of possessing similar or improved mechanical properties to their petroleum-based counterparts. As such, normalized environmental impacts to material properties indicated that bio-based composites could lead to desirable combined mechanical and environmental attributes for certain applications. Considering the differences between environmental impact categories and uncertainties in environmental impact assessments, selection of constituents cannot be based solely on material feedstock to mitigate environmental impacts in wood fiber composites. Conclusions Findings indicate that both environmental impact assessments and mechanical properties should be considered concurrently to effectively distinguish the benefits of selecting petroleum-based or bio-based plastics. This work shows that depending on the intended application, the selection of a bio-based feedstock could either be beneficial for mitigating certain environmental impacts, have little effect on impacts, or increase environmental impacts. These findings reveal the importance of considering property alteration and multiple effects of utilizing these resources.

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木纤维复合材料与生物基或石油基塑料的环境属性

目的 虽然生物基复合材料（用天然纤维增强的生物基塑料）已被讨论为石油基塑料复合材料的潜在可持续替代品，但对这些材料的定量环境影响评估很少。这项工作对石油基塑料和生物基塑料及其复合材料进行了比较，以 (1) 评估塑料和复合材料生产对环境的影响，以及 (2) 确定通过生产生物基复合材料可以减轻哪些环境影响，基于关于目前的制造方法。方法 进行环境影响评估以确定与生物基和石油基塑料及其与木粉（即锯末）填料的复合材料的从摇篮到门生产相关的负担。这项工作的范围包括热塑性塑料和木粉生产以及造粒、成型和运输过程的排放。使用美国环境保护署的 TRACI 方法评估了几个影响类别的环境影响。使用量化的影响以及来自文献中 36 个来源的材料特性数据，对复合材料类型进行了比较。使用了多个功能单元，包括生产的恒定质量的材料和两种通过材料特性对环境影响进行标准化的比较方法。进行了不确定性评估以确定每种塑料和木纤维复合材料类型的环境影响分布。结果与讨论 在以下几个影响类别中，生物基塑料及其复合材料的生产对环境的影响低于石油基塑料和复合材料：全球变暖潜势、化石燃料消耗和某些人类健康影响。然而，生物基塑料及其复合材料的生产也导致了一些更高的环境影响，例如富营养化。生物基复合材料能够拥有与其石油基复合材料相似或改进的机械性能。因此，归一化环境对材料特性的影响表明，生物基复合材料可以为某些应用带来理想的机械和环境属性组合。考虑到环境影响类别和环境影响评估中的不确定性之间的差异，成分的选择不能仅仅基于材料原料来减轻木纤维复合材料的环境影响。结论 结果表明，应同时考虑环境影响评估和机械性能，以有效区分选择石油基塑料或生物基塑料的好处。这项工作表明，根据预期应用，选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。成分的选择不能仅仅基于材料原料来减轻木纤维复合材料对环境的影响。结论 结果表明，应同时考虑环境影响评估和机械性能，以有效区分选择石油基塑料或生物基塑料的好处。这项工作表明，根据预期应用，选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。成分的选择不能仅仅基于材料原料来减轻木纤维复合材料的环境影响。结论 结果表明，应同时考虑环境影响评估和机械性能，以有效区分选择石油基塑料或生物基塑料的好处。这项工作表明，根据预期应用，选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。结论 结果表明，应同时考虑环境影响评估和机械性能，以有效区分选择石油基塑料或生物基塑料的好处。这项工作表明，根据预期应用，选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。结论 结果表明，应同时考虑环境影响评估和机械性能，以有效区分选择石油基塑料或生物基塑料的好处。这项工作表明，根据预期应用，选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或者增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。选择生物基原料可能有利于减轻某些环境影响，对影响几乎没有影响，或者增加环境影响。这些发现揭示了考虑财产变更和利用这些资源的多重影响的重要性。