Comparative Life Cycle Assessment of Different Production Processes for Waterborne Polyurethane Dispersions

Abstract

Waterborne polyurethane dispersions (PUDs) have gained significant importance in the coating industry due to their diverse chemical and physical properties. However, a comprehensive analysis of their environmental impacts is lacking. Therefore, this study provides a comparative life cycle assessment (LCA) of four different PUD production processes from cradle-to-gate. The environmental performances of the NMP process, the acetone process, the melt process, and a conceptualized continuous flow process were evaluated and compared following the CML 2001 methodology. The LCA revealed that the conceptualized flow process exhibits the lowest environmental impact in all investigated impact categories. Depending on the impact category, the melt process or the acetone process rank second. The NMP process was observed to have the highest impact in all categories. Consequently, the flow process has the lowest carbon footprint (1.13 kg CO2-eq), according to the global warming potential (100 years), followed by the melt (1.45 kg CO2-eq), the acetone (1.95 kg CO2-eq), and the NMP process (3.11 kg CO2-eq).