Environmental impact and cost of bio-based hydrophobic multifunctional coatings

The circular bioeconomy supports climate action by promoting the use of renewable materials in sustainable production. In this study, bio-based betulin, lignin, and suberin were used as raw materials for producing the multifunctional hydrophobic coatings. Life cycle assessment (LCA) was used to study the environmental impact of these protective coatings from cradle to gate. The foreground data were collected from laboratory experiments and literature, while background data were sourced from the ecoinvent 3.10 database. The functional unit (FU) used was coating production and application on 1 m² of fabric. The environmental impacts and cost were evaluated using Recipe (H) 2016 midpoint method in SimaPro 9.6. The results indicated that per FU, the global warming potential (GWP) was 2.92 kg CO₂ eq. for suberin coating, 2.39 kg CO₂ eq. for betulin coating, and 2.01 kg CO₂ eq. for lignin coating. The sensitivity analysis was conducted and indicated that replacing ethanol with bioethanol reduced the burden on GWP and fossil resource scarcity (FRS) but increased the burden on land use (LU), terrestrial ecotoxicity (TE), and human non-carcinogenic toxicity (HNCT). Additionally, the source of energy in the process, particularly the participation of nuclear and bio-based electricity, was found to influence the results on GWP, IR, and LU impact categories. The recycling rate of solvents and the production process of feedstocks (suberin, betulin, and lignin) significantly impacted the results.