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

A novel ricinoleic acid (RA) based phosphorus and nitrogen-containing flame retardant polyols (FRPE) was successfully synthesized and characterized by FTIR, 1H NMR and 13C NMR. The flame retardant polyurethane sealants (FR-PUS) were prepared by curing FRPE with methylene diphenyl diisocyanate (MDI-50). The flame retardant properties and thermal decomposition of FR-PUS were investigated by the limiting oxygen index (LOI), cone calorimeter testing (CCT) and thermogravimetric analysis (TGA). The results showed that FRPE could enhance the thermal stability and improve the flame retardancy of polyurethane sealants (PUS) without any other flame retardant. Moreover, the gaseous degradeation products of FR-PUS were analyzed by thermogravimetric analysis/infrared spectrometry (TG-IR), providing insight into the thermal degradation mechanism. FTIR and dynamic mechanical analysis (DMA) were used to explore the chemical components of the char after CCT and mechanical properties of PUS.