Preparation and Tensile Properties of Citric Acid Crosslinked Poly(vinyl alcohol) films reinforced with Nano‐Alumina

Abstract

Poly(vinyl alcohol) is widely used in many industrial applications due to its attractive physico‐chemical properties. However, water solubility and limited mechanical strength may sometimes restrict its usage. In the present study, an attempt has been made to improve the mechanical properties of the poly(vinyl alcohol) films, particularly the tensile strength, the percentage elongation and Young's modulus. Poly(vinyl alcohol) films were prepared by solution casting. Citric acid is used as a crosslinker and nano‐alumina (0.1–1% w/w) has been added as reinforcement in the crosslinked matrix. Compared to uncrosslinked films, the films containing citric acid demonstrate an increase of ~10% and ~38% in the tensile strength and modulus, respectively. Nano‐alumina acted as a suitable reinforcement and enhanced the tensile strength and modulus of crosslinked film by ~20% and ~27%, respectively, at 0.3% (w/w) loading. Uncrosslinked film dissolved in distilled water whereas the crosslinked films underwent swelling which reduced with the addition of nano‐alumina. Crosslinked poly(vinyl alcohol) films reinforced with nano‐alumina thus possess superior properties compared to both uncrosslinked and crosslinked films. The crosslinked nanocomposite films could find immense use as a food packaging material or in making membranes for water desalination.Highlights Poly(vinyl alcohol) chemically crosslinked by citric acid. Nano‐alumina added as reinforcement in crosslinked poly(vinyl alcohol) film. Swelling studies conducted on crosslinked nanocomposite films. Tensile testing results showing the supremacy of crosslinked nanocomposite films over uncrosslinked and crosslinked pure film.