Preparation and Characterization of Sweet Potato Residue based on NIPU

This research explores the synthesis of non-isocyanate polyurethane (NIPU) materials using sweet potato residue as a biomass-based raw material. The study involves a multi-step process, including oxypropylation and epoxidation reactions to activate hydroxyl groups within sweet potato residue, resulting in hydroxyl-activated sweet potato residue oil (HAPO). Subsequently, HAPO is further modified through epoxidation, leading to epoxidized HAPO (Expo-HAPO). These intermediate products are then utilized in the preparation of NIPU films by cross-linking with various polyamines. The study emphasizes the importance of maintaining specific molar ratios for optimal cross-linking. Characterization techniques, such as FT-IR and 1H-NMR, confirm the successful reactions and molecular changes during the process. Additionally, the incorporation of lignin oil enhances mechanical properties and UV resistance in the NIPU films. This research expands the application scope of NIPU materials, making them more environmentally friendly and versatile.