A Cradle-to-Gate Life Cycle Assessment of Sustainable All-Cellulose Composites Using Imidazolium-Based Ionic Liquid.

All-cellulose composites (ACCs) are single-component bio-based green composites made from cellulose, enabling simplified recycling because ACCs have no chemical incompatibility between their matrix and reinforcement fibers. Yet, few life cycle assessment (LCA) studies have examined environmental performance of ACCs. This study assessed the ACC sustainability through a cradle-to-gate LCA following the ISO 14040: 2006 framework. ACCs were produced via cellulose dissolution in either stand-alone ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc) or with its co-solvent dimethyl sulfoxide (DMSO). DMSO served as a co-solvent to reduce the EMIM OAc viscosity and improve cellulose dissolution. The E60D40 solvent (60 wt.% EMIM OAc, 40 wt.% DMSO) exhibited the lowest global warming potential (GWP) at 0.25 kg CO2 eq/FU, whereas the E20D80 had the highest at 0.75 kg CO2 eq/FU, exceeding stand-alone EMIM OAc (0.33 kg CO2 eq/FU), where FU is the equivalent mass of ACCs. Human health, ecosystem quality, and resource scarcity impacts ranged from 5.06 × 10-7-1.56 × 10-6 DALY/FU, 1.15 × 10-9-3.94 × 10-9 species.yr/FU, and 2.70 × 10-2-8.20 × 10-2 USD2013/FU, respectively across different solvent scenarios. These findings illustrate that ACC development can be made more sustainable with DMSO's influence over pure EMIM OAc type solvent formulations.