Thermal and Mechanical Evaluations of Innovative Polyurethane Materials and Its Precursors Based on Moringa oleifera Oil

Abstract

This study highlights the synthesis of innovative polyurethane materials derived from Moringa oleifera oils extracted from two distinct sources. The oils were converted into their respective polyols through the in situ generated performic acid method. Diverse material characteristics were observed due to different agroclimatic and cultivation conditions for the sources. Extraction yields were 45.21% (source 1) and 40.32% (source 2), with acid values of 28.70 and 26.00 mg KOH per g of oil, respectively. Oleic acid constituted 79.87 and 67.11% of the oils composition, respectively. Nuclear magnetic resonance and Fourier transform infrared spectroscopy (FTIR) confirmed the hydroxylation of the oils. FTIR also identified the isocyanate structures in the synthesized polyurethane materials. Gel permeation chromatography analysis revealed a higher oligomer content in the polyol synthesized from the oil extracted from source 2. Thermogravimetric analysis demonstrated enhanced thermal stability post-oil conversion, highlighting decomposition stages for rigid and flexible segments. Differential scanning calorimetry indicated higher unsaturation in the oil extracted from source 1, resulting in an elevated crystallization temperature. Tensile testing showed increased elasticity as the [NCO]/[OH] ratio decreased in the material, emphasizing the influence of polyol and crosslinking agent concentrations on mechanical resistance of polyurethane materials.