Fabrication of castor oil-derived polyurethane mortar composites with energy saving and sound absorption characteristics

Polyurethane (PU) consists of an organic chain unit joined by carbamate (-NHCOO-) links. A variety of raw materials are used in addition to castor oil to produce polyurethane foam composites. In this attempt, poly-hydroxyl compound (petroleum-based polyol) was substituted by natural oil (plant-based polyol) with 0 – 100 wt.% replacement to fabricate semi-rigid polyurethane foam composites. The polyurethane foam derived from castor oil (PU-CO) was characterized using infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, compression strength, tensile strength and density, respectively. The cement mortar containing polyurethane semi-rigid foam composites based on castor oil (CM-PU-CO) were also studied using infrared spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller (BET) analysis, powder X-ray diffraction, thermogravimetric analysis, thermal conductivity and sound absorption coefficient. The results indicated that CM-PU-CO composites are promising energy-saving materials, particularly under harsh climatic conditions, till 50% partial replacement with castor oil. The substitution of petroleum-based poly-hydroxyl compounds with a natural-based polyol, such as castor oil, was very promising.