Enhancing polyvinyl alcohol surface properties through pre-drying treatment and modified electrospun polycaprolactone nanofibers

Abstract

The application of polyvinyl alcohol (PVA) as a biodegradable polymer is restricted by its low water resistance, particularly for the packaging of moisture-sensitive products. In this paper, we report on a surface-modification approach for PVA films using electrospinning of beeswax-modified polycaprolactone (PCL) following a 10 min pre-drying process. The pre-drying process led to physical binding between the hydrophobic PCL/beeswax nanofibers and the hydrophilic PVA substrate while the addition of beeswax to PCL improved its physical properties, leading to larger surface roughness and lower wettability of the PVA film. In particular, by adding a proper amount of beeswax to PCL, a PVA/PCL/beeswax composite film showed high hydrophobicity with a water contact angle of 144.1°, demonstrating a significant improvement in the surface properties compared to the hydrophilic bare PVA film. Moreover, the oxygen permeability of the PVA film decreased from 5.5 to 2.2 cc.m−2.day−1 after electrospinning the PCL/beeswax, which was related to the rougher surface morphology generated by the electrospun nanofibers. Therefore, our cost-effective approach has the potential to modify the physical properties of hydrophilic polymers and to broaden their industrial applications.