A detailed LCA-contribution analysis was conducted to identify the contribution of each component in the preparation of M1 and M2 (Fig. and). For M1, electricity is the major contributor, followed by PMMA-co-PCMSt, and nonwoven polyester fabric. Electricity is also a major contributor to M2, followed by PMMA-co-PCMSt, H3CO-PEG-NCO, isopropanol (IPA), and NMP. The syntheses of PMMA-co-PCMSt and H3CO-PEG-NCO require large amounts of electricity and toxic solvents (Tables and). The contribution analysis for PMMA-co-PCMSt synthesis (Fig. ) shows that electricity consumption is a major contributor in all impact categories. The midpoint analysis indicates that electricity and solvents are two major hotspots during PMMA-co-PCMSt synthesis and membrane fabrication.