Synthesis of a novel phosphorus and nitrogen-containing bio-based polyol and its application in flame retardant polyurethane foam

Abstract

A novel, castor oil (CO)-based, flame-retardant polyol containing phosphorus and nitrogen was successfully synthesized. The novel polyol was characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), and carbon-13 nuclear magnetic resonance (13C NMR) spectroscopies. Flame-retardant polyurethane foams (FRPUF) were prepared by curing flame retardant polyols (FRPE) and flame retardant dihydric alcohol (BHAPE) with polyisocyanate (PM-200). The flame retardant properties and thermal decomposition of FRPUF were investigated using the limiting oxygen index (LOI), cone calorimeter testing, and thermogravimetric analysis (TGA). The FRPE and BHAPE composites were found to enhance the thermal stability and flame retardancy of polyurethane foams (PUF) without the use of other flame retardants. Insight was gained into the gaseous degradation products of FRPUF using thermogravimetric analysis-infrared spectrometry (TG-IR) and thermogravimetric analysis-mass spectrometry (TG-MS). The character of polyurethane foams was explored using FTIR, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Gas-phase pyrolysis products were investigated by TG-IR and TG-MS. Good flame retardancy was observed in FRPUF, which was attributed to the flame retardant FRPE and BHAPE.