Journal of Applied Polymer Science, Vol.108, No.1, 245-255, 2008
Thermally stable polyurethane-ureas and copolyurethane-ureas containing zinc and nickel dihydroxysaltrien complexes
New 4,4'-dihydroxysaltrien metal complexes, (MOHSal(2)trien, where M = Zn and Ni) were synthesized and used for the synthesis of metal-containing polyurethane-ureas and copolyurethane-ureas. MOHSal(2)trien underwent polymerization reaction with two diisocyanates, namely 4,4'-diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI) to yield polyurethane-ureas. Copolyurethane-ureas were synthesized by the reaction between MOHSal(2)trien, MDI, and diamines or dialcohols. The diamines or dialcohols employed were 4,4'-methylene-dianiline (MDA), hexamethylenediamine (HMA), bisphenol A (BPO), and hexamethylene glycol (HMO). The polymers were characterized by IR, NMR, elemental analysis, XRD, solubility, and viscosity. Thermal stability and flammability of polymers were studied by thermogravimetric analysis (TGA) in air and by measuring limiting oxygen index (LOI) values, respectively. It was found that the resulting metal-containing polyurethane-ureas and copolyurethane-ureas exhibited good thermal stability. Among all metal-containing polyurethane-ureas, NiOHSal(2)trien-MDI was the most thermally stable polymer with char yield of 55% at 600 degrees C. Solubility in DMSO of zinc-containing copolyurethane-ureas based on dialcohols was greatly improved when compared with those of zinc- and nickel-containing polyurethane-ureas. ZnOHSal(2)trien-MDI-BPO and ZnOHSal(2)trien-MDI-HMO gave high char yield of 46% at 600 degrees C, which is almost comparable with that of NiOHSal(2)trien-MDI (c) 2007 Wiley Periodicals, Inc.
Keywords:polyurethane-ureas;metal-containing polymers;thermally stable polymers;thermogravimetric analysis