Tensile strength of electrospun Poly(ethylene-co-vinyl alcohol) nanofibre sheets

Electrospinning technology was used to obtain non-woven sheets made from fine fibres in a controllable diameter range from 50 nm to 3 mu m. Poly(ethylene-co-vinyl alcohol), a large molecule polymer was chosen to make the fibres for its biodegradable and biocompatible properties. The thin sheets obtained were tested in uniaxial tension for their mechanical properties in view of the potential use as wound dressings. It is found that the sheets show a mild hardening behavior with extensive elongation and necking before failure in multiple fractures at random locations. Due to the random orientation of the continuous fibres in the sheet, detachment, shear, straightening and twinning. etc., occur amongst fibres to different extends at the same time. The Young's modulus and the yield stress (at 0.4 similar to 0.5% proof strains) are predominately affected by fibre diameters, and are largely insensitive to strain rate over the range tested.