Preparation and characterization of palm oil-based polyurethane foam using polysorbate as a green ring-opening agent

The increasing environmental concerns, together with the depletion of fossil resources, have led to an increased interest in exploring alternatives for petroleum-based polyols to produce polyurethane (PU). This research addresses this challenge by producing flexible-to-semi-rigid PU foams using 100 % palm oil-based polyol (POP), derived from epoxidized palm oil (EPO) through a green ring-opening reaction facilitated by polysorbate 20, a non-ionic surfactant that enhances chain mobility and reduces surface tension. The POP was characterized using oxirane oxygen content, hydroxyl value, FT-IR NMR, and DSC, confirming successful epoxidation and ring-opening. Incorporating varying EPO contents in PU foams revealed significant effects on foam morphology, thermal stability, and mechanical properties. FT-IR analysis confirmed increased urethane linkage formation, while DSC and XRD indicated enhanced partially ordered arrangements. Foams with 75 % EPO exhibited a 25 % improvement in compressive strength (121.6 kPa vs. 97.3 kPa at 25 % EPO) and increased degradation onset temperature to 339°C. However, resilience decreased from 21.7 % to 14.5 % due to enhanced phase mixing and rigidity. These findings demonstrate the feasibility of fully bio-based PU foams with tunable properties and highlight the potential of polysorbate 20 as a green, multifunctional agent for sustainable polymer development.