Inelastic deformation of highly aligned dry-spun thermoplastic polyurethane elastomer microfibres

The present study focuses on the fabrication and mechanical responses of highly aligned thermoplastic polyurethane microfibres. A facile dry spinning assisted by an electrical field technique was used to fabricate these microfibres. The surface morphology of the microfibres were inspected under a scanning electron microscope, while their mechanical responses were probed using universal tensile machine. The mechanical tests include uniaxial monotonic, cyclic with increasing maximum strain and relaxation tensile tests using two different strain rates: 0.1 s −1 and 0.001 s −1 . According to the surface morphology study, the fibres are highly aligned with the diameter of 2.80 ± 0.06 μ m and without beads. As for mechanical tests, the fibres show inelastic mechanical responses such as hysteresis, stress-softening, stress relaxation and residual strain. Except for its nearly linear stress-strain response before reaching ultimate tensile strength, it appears that the thermoplastic polyurethane elastomer microfibres exhibit general features commonly found in bulk elastomers. The findings in this study are expected to provide a basis for the modelling of the mechanical behaviours of elastomer fibres in the future.