Synthesis and Characterization of Polyesterurethanes and Their Applications to Flame-Retardant Coatings

This work describes the synthesis of novel phosphorous-containing polyester polyols and their characterization by various techniques. Polyester was prepared by the reaction of tris (bisphenol-A) monophosphate, maleic anhydride, and phthalic anhydride. This polyester was reacted with various diols like ethylene glycol, diethylene glycol, and propylene glycol to obtain polyester polyols. Synthesized polyester polyols were characterized by chemical analysis and instrumental analysis techniques and used further to react with different isocyanates like toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HMDI) to develop polyesterurethane coatings on mild steel panels. The flame-retardant properties of cast films were determined by limiting oxygen index analysis and UL-94 test methods. The physical and mechanical properties of polyesterurethane coatings such as pot life, drying properties, scratch hardness, pencil hardness, impact resistance, adhesion, and flexibility were investigated. In addition, the chemical resistance properties of coatings were also determined. The data reveal that polyesterurethanes hold promise for use as effective flame-retardant coatings.