PHYSICO-MECHANICAL, OPTICAL, AND WAXS STUDIES ON CHAIN EXTENDED POLYURETHANE

Thermoset polyurethane (PU) elastomers were prepared using castor oil, 4,4′-methylenebis(phenyl isocyanate) (MDI), and tol-uene-2,4-diisocyanate (TDI). The effect of aromatic diamines on the physico-mechanical and optical properties of chain extended polyurethane prepared using castor oil has been investigated. Tensile strength and percent elongation lies in the range 13-24 MPa and 76-32, respectively. Higher tensile strength was observed for 4,4′-diaminodiphenylsulphone (DDS) than the 4,4′-diaminodiphenylmethane (DDM) chain extender. The properties imparted by the extenders are explained on the basis of the groups present in the diamines. These changes have been interpreted quantitatively in terms of microcrystalline parameters computed using wide-angle X-ray scattering data.