Studies on calcium-containing poly(urethane ether)s

The calcium salt of mono(hydroxyethoxyethyl)phthalate [Ca(HEEP)(2)] was synthesized by the reaction of diethylene glycol, phthalic anhydride, and calcium acetate. Calcium-containing poly(urethane ether)s (PUEs) were synthesized by the reaction of hexamethylene diisocyanate (HMDI) or tolylene 2,4-diisocyanate (TDI) with a mixture of Ca(HEEP)(2) and poly(ethylene glycol) (PEG(300) or PEG(400)) with di-n-butyltin dilaurate as a catalyst. A series of calcium-containing PUEs of different compositions were synthesized with Ca(HEEP)(2)/PEG(300) (or PEG(400))/diisocyanate (HMDI or TDI) molar ratios of 2:2:4, 3:1:4, and 1:3:4 so that the coating properties of the PUEs could be studied. Blank PUEs without calcium-containing ionic diols were also prepared by the reaction of PEG(300) or PEG(400) with HMDI or TDI. The PUEs were well characterized by Fourier transform infrared, H-1 and C-13 NMR, solid-state cross-polarity/magic-angle-spinning C-13 NMR, viscosity, solubility, and X-ray diffraction studies. The thermal properties of the polymers were also studied with thermogravimetric analysis and differential scanning calorimetry. The PUEs were applied as top coats on acrylic-coated leather, and their physicomechanical properties were also studied. The coating properties of PUEs, such as the tensile strength, elongation at break, tear strength, water vapor permeability, flexing endurance, cold crack resistance, abrasion resistance, color fastness, and adhesive strength, were better than the standard values. (C) 2003 Wiley Periodicals, Inc.