Valorisation of Waste Cooking Oil (WCO) as a Bio-Polyol Precursor for Polyurethane Foam Production

The valorisation of food waste into high value chemicals is a key strategy for the circular economy [1], with waste cooking oil (WCO) emerging as a particularly valuable resource to produce polyurethane foam [2]. In this research, WCO was converted into a mixture of 70% monoglycerides, 25% diglycerides, and 5% triglycerides via an eco-friendly and cost-effective glycerolysis process using NaOH as the catalyst. After the removal of unreacted glycerol, the resulting glyceride mixture (Bio-PO) was successfully reacted with a bio-based isocyanate to obtain polyurethane foam. The synthesis was initially performed on a small scale using cylindrical molds to screen different formulations. The process was subsequently scaled up to produce 20x20x5 cm foam blocks at NCO/OH ratios of 1.4, 1.2, and 0.9, demonstrating high reproducibility. Finally, all the synthesized foams were comprehensively characterized to evaluate their chemical structure, morphology, density, thermal stability, and mechanical properties.