A novel biopolyurethane foam synthesized from Pterocarya stenoptera seed oil and polyethylene glycol and its efficient application for oil-water separation

Polyurethane foam (PUF) is widely used across industrial sectors due to its lightweight structure and tunable mechanical properties; however, its conventional synthesis depends heavily on petroleum-based polyols. Developing renewable and sustainable polyols is therefore essential for advancing green polyurethane technology. Herein, we report a novel biopolyurethane foam (POPUF) synthesized from Pterocarya stenoptera seed oil via a thiol-ene photo-click reaction. The P. stenoptera seed oil polyol (POP) exhibited a hydroxyl value of 119 mg KOH·g −1 under optimized conditions (12 h reaction time, 4:1 M ratio of mercaptoethanol to C=C). Substitution of polyethylene glycol 400 (PEG-400) with POP yielded foams with adjustable pore morphology and improved physicochemical performance. At 15 wt% POP addition, POPUF displayed a reduced pore size (172 ± 30 μm), increased density (138.6 kg m −3 ), and higher water uptake (4.20 g g −1 ). Thermal analyses confirmed enhanced crosslinking, greater ester content, and increased soft-segment flexibility, contributing to superior thermal stability. TiO 2 nanoparticles and polydimethylsiloxane (PDMS) were sequentially deposited onto POPUF to impart selective wettability for separation applications. The modified foam demonstrated rapid adsorption kinetics (<30 s), solvent uptakes up to 21.45 g g −1 , excellent recyclability (>94% retention after 20 cycles), and outstanding oil-water separation efficiency (>98.3% under static and gravity-driven conditions). This study demonstrates an efficient and sustainable approach for converting underutilized seed oil into a high-performance bio-based polyurethane foam, offering a promising pathway toward renewable polymeric materials for environmental and separation applications.