MECHANICAL-BEHAVIOR AND MORPHOLOGY OF A POLYETHERPOLYURETHANE

A thermoplastic polyetherpolyurethane was studied in the as-moulded and annealed states. The degree of phase separation that occurs on annealing was characterised by small angle x-ray scattering (SAXS) and solid state nuclear magnetic resonance (NMR). Differential scanning calorimetry (DSC) was used to characterise the degree of order in the hard segment phase. SAXS and NMR indicate that phase separation occurs within the first five minutes of annealing at 155 degrees C. DSC indicates that hard segment ordering continues after phase separation and is essentially completed after 120 minutes of annealing. The effect of phase separation (the development and ordering of interfaces between hard and soft segments) is contrasted with the effect of hard segment ordering (the development of order within the hard segment phase) on the mechanical and wear properties of this polyurethane.