Synthesis and analysis of lactose polyurethanes and their semi-interpenetrating polymer networks

Abstract

In view of growing public awareness of environmental pollution, plastic waste, and microplastics, agro-based materials are increasingly used to replace raw materials derived from fossil feedstocks in order to take advantage of their sustainability, eco-friendliness, better recyclability, and lack of toxicity. One of our focal areas is lactose, which is the natural disaccharide found in milk; it is inexpensive and widely available. In this work, we synthesized polyurethanes from lactose and toluene-2,4-diisocyanate (TDI), using both conventional heat and microwave. Microwave was found to reduce the reaction time and save energy relative to conventional heat. Moreover, semi-interpenetrating polymer networks were made with a second polymer {e.g., poly(vinyl pyrrolidone) and poly(lactic acid)} in order to impart additional properties to the lactose-based polyurethanes. The resulting polymers were characterized with appropriate analyses.