Preparation and Characterization of Polyurethane Rigid Foam Nanocomposites from Used Cooking Oil and Perlite

Modern chemical industries trend towards industrial ecology to achieve a circular economy, because of increasing environmental and economic awareness jointly. One of the most important of these industries is polyurethane, accompanied by more and more interest in using renewable polyols. The study focuses on synthesizing and characterizing polyurethane rigid foams formulated by replacing 40%, 60%, and 100% of a petrochemical polyol with a bio-polyol derived from used cooking oil, and introducing perlite and modified perlite nanoparticles into the bio-polyol. The products were evidenced by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), nuclear magnetic resonance spectral analyses, thermogravimetric analysis (TGA), and scanning electron microscopy equipped with energy-dispersive spectroscopy. The results indicate that the hydroxide value and viscosity at 25°C of the bio-polyol were around 456 ± 30  mg KOH/g and 148 mPa s. Bio-polyol blends of 40% and 60% had no significant effect on the thermal properties of polyurethane systems. The lowest value of char yield was observed for the sample with a 100% bio-polyol content of 2.3%. The beneficial effects of both perlite and modified perlite particles on the 100% bio-polyol-based foam were observed as having an effective role in improving thermal stability and reconstructing cellular structure. The yield char increased to 13.2%, 14%, 14.7%, and 15% for the two filler contents 2.5% and 5%. However, the new bio-polyol has a fairly good value in industrial construction, and the perlite particles have enhanced and improved this value.