Molecular dynamics, thermo-mechanical and optical studies on benzidine chain extended polyurethane-urea

Abstract

This paper reports the effect that the aromatic diamines and crosslinker nature have on the physico-mechanical and dielectric properties of linear and crosslinked polyurethane-urea. These elastomers were prepared using poly(tetramethylene glycol) (Terathane 1400), 1,6-hexamethylene diisocyanate and 4,4′-diaminobiphenyl (benzidine) as chain extender and glycerin or castor oil as crosslinkers. The polyurethane-ureas were characterized through Fourier transform infrared spectroscopy, thermogravimetric analysis, differential dynamic mechanical analysis, dielectric properties. The effects of the hard segments structure on physical, dielectric, mechanical and dynamic mechanical properties of the polyurethane-urea elastomers were investigated. The presence of more urea groups in the hard segment leads to high tensile strength (60–70 MPa), high elongation (700%–950%), increased thermally stability and superior dielectric properties.