Electrospinning and characterisation of poly(vinyl alcohol) blend submicron fibres in aqueous solutions

Poly(vinyl alcohol) (number-average degree of polymerisation 1700 (PVA-17) and 4000 (PVA-40)) blend submicron fibres were fabricated by the electrospinning method in an aqueous solution of 5-10% polymer concentration. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were utilised to characterise the morphology and physical properties of the PVA fibres. The role of PVA blend mass ratio and concentration and of processing parameters such as applied voltage and capillary-to-collector distance in the production of ultrafine submicron PVA blend fibres was investigated. Uniform PVA fibres with an average submicron-scale diameter (250-600 nm) could be prepared from a 7.5% PVA-17/PVA-40 blend solution with various mass ratios. With a lower PVA blend concentration (5%), using different PVA-17/PVA-40 mass ratios, beads appeared in the fibre morphology, and homogeneity was also absent. At a higher PVA blend concentration (10%), larger-diameter (<700 nm) ribbon-like fibres were produced. Moreover, with a higher percentage of PVA-40 in the PVA blend fibres, superior crystallinity, thermal stability, and mechanical properties could be obtained by comparison with PVA-17.