Mind the gap: Improvement of the life cycle inventory for epoxy resins

Kurzfassung

Sustainability demands for lightweight structural materials now routinely call for life-cycle assessment (LCA) to quantify potential environmental burdens. Fibre-reinforced plastics (FRPs) are especially challenging because proprietary manufacturing data are rarely disclosed, leading to incomplete or missing primary information. A critical bottleneck is the construction of a robust Life-Cycle Inventory (LCI) for epoxy resin systems, which are characterized by a wide range of hardeners, reactive diluents, and other additives. Consequently, many LCA practitioners resort to proxy data that may not reflect the specific chemical composition of the resins in question. This study examines the implications of using such imprecise data and the resulting uncertainties by conducting a cradle-to-gate life cycle assessment (LCA) of three commercially relevant epoxy resin systems. First, a modelling strategy is developed in which the selection of databases and data sources is tailored to the properties of each resin system. Using this strategy, a detailed LCI is created for each resin, taking into account all relevant chemical compounds contained therein. The environmental impact assessment is then carried out, with results parsed by individual resin components and correlated with their chemical structures. To benchmark the sensitivity of the outcomes, the results are compared against a proxy dataset and subjected to a sensitivity analysis in accordance to DIN EN ISO 14044. The analysis reveals that variations in additives, curing agents, and production processes can significantly alter impact indicator results across key categories such as global warming potential, resource depletion, and human toxicity. The findings underscore the necessity of developing comprehensive, LCIs for synthetic resins and highlight that overlooking these factors may lead to misleading sustainability conclusions. Future LCA work should therefore prioritize accurate, system-specific data acquisition to ensure reliable environmental evaluations of epoxy-based lightweight composites.