Comparative Environmental Life Cycle Assessment on Corn Starch Plasticization and Co-Plasticization Processes

Abstract

Starch has overtaken the bioplastic market in developing thermoplastic starch-based blends and composite systems owing to its biodegradability and sustainability. Thermoplastic starch (TPS) development is mostly a two-stage process involving plasticizing starch and blending plasticized starch with a polymer. Most of the research focuses on improving the properties of the blend system through different methodologies, including various plasticizers and co-plasticizers. However, limited studies have analyzed the environmental effects of plasticizers or co-plasticizers and their processing. Thus, in this research, the environmental impact of starch plasticization processes performed by co-plasticization (glycerol–urea, glycerol–citric acid, and glycerol–succinic anhydride) and by conventional glycerol-based plasticization is compared through life cycle assessment (LCA). The results showed that glycerol–citric acid- and glycerol–succinic anhydride-based co-plasticization had a comparable environmental impact to traditional glycerol-based plasticization. In contrast, the glycerol–urea-based co-plasticization process exhibited the highest effect on the environment. Furthermore, to reduce the environmental impact, a sensitivity analysis of the plasticization processes was conducted by changing the energy aspect of the processes through quantitative and qualitative approaches. The qualitative approach significantly reduced major impact categories such as global warming, carcinogens, ecotoxicity, and fossil fuel depletion.