Synthesis of polyurethane-ureas containing 4,4'-dihydroxysalcyclohexane zinc and copper complexes

Abstract

4,4 ́-Dihydroxysaltetraen metal complexes (ML₁, M = Mn and Co) have been synthesized by the reaction between 2,4-dihydroxybenzaldehyde, manganese or cobalt acetate and tetraethylenepentamine. These metal complexes were characterized by IR spectroscopy and elemental analysis. It was found that the metal complexes were mixture of many products which could not be purified. Therefore, 4,4 ́-dihydroxysalcyclohexane metal complexes (ML₂, M = Zn and Cu) have been synthesized by the reaction between 2,4-dihydroxybenzaldehyde, zinc or copper acetate and 1,2-diaminocyclohexane. These metal complexes were characterized by IR spectroscopy, ¹H NMR spectroscopy, mass spectrometry and elemental analysis. Metal-containing polyurethanes have been synthesized by the polymerization reaction between ML2 and different prepolymers using dibutyltin dilaurate as a catalyst. The employed prepolymers were tolylene 2,4-diisocyanate terminated poly(1,4-butanediol) prepolymer with MW 900 (PB900) and tolylene 2,4-diisocyanate terminated poly(propylene glycol) prepolymer with MW 1,000 (PP1000). Polyurethane-ureas with and without metal in the main chain were also synthesized to compare the properties with synthesized metal-containing polyurethanes. The progress of polymerization reaction was followed using IR spectroscopy. The disappearance of isocyanate peak at 2275 cm̄¹ was observed when the polymerization was completed. The solubility and thermal stability by thermogravimetry of the polymers were also studied.