NANOCOMPOSITES OF SEGMENTED POLYURETHANES INCLUDING POLY (2-ALKYL-2-OXAZOLINE) SEQUENCES WITH MONTMORILLONITE

Abstract

A series of polyurethane/montmorillonite nanocomposites have been synthesized using poly(tetramethyleneglycol), α, ω-dihydroxylated poly(2-alkyl-2-oxazoline), 4,4-diphenylmethane diisocyanate or 4,4-dicyclohexylmethane diisocyanate and montmorillonite. The inorganic component was added after the polyurethane synthesis or during its preparation (in situ polymerization). The influence of the composition,of the monmorillonite amount and of the preparation approach on the dispersion degree of the clay in the polymer matrix and implicitely on the mechanical strength of the new materials was studied by means of spectral and thermal analysis, X-ray diffraction and dynamic-mechanical analysis. The development of H-bonds and of specific montmorillonite- poly(2-alkyl-2-oxazoline) sequence interactions were found to be the cause for improved mechanical properties of the corresponding polyurethanes and their nanocomposites with the inorganic compound.