Effect of nanocellulose on mechanical and barrier properties of PVA–banana pseudostem fiber composite films

Abstract

PVA–Banana pseudostem fiber lignocellulosic composite films were prepared by solution casting method and reinforced with increasing amount of nanocellulose filler for enhancement of mechanical and barrier properties. The nanocellulose filler was derived from microcrystalline cellulose via a green synthesis route avoiding use of concentrated acid in conventional process. Composite films showed remarkable improvement in mechanical properties like tensile strength and elongation at break. Water barrier properties were also improved as evident by the reduction in swelling percentage and water vapour permeability. Film transparency was somewhat reduced due to the cross linking formed by the nanocellulose particles. Overall a maximum improvement of 14.3% was observed in tensile strength of films reinforced with 3 wt% nanocellulose while the elongation at break reduced by 9.1% percent for the same. Water vapour permeability improved by 29.7%, the decrease being inversely proportional to amount of nanocellulose added. Water swelling test showed promising results as weight gain by the film was limited to only 16.8% after immersion in water for 24 h as compared to 67.4% weight gain by the PVA–lignocellulosic composite films containing no nanocellulose. Our results show that nanocellulose addition to PVA–banana pseudostem fiber composite films significantly improve their mechanical and water barrier properties making them a suitable alternative to plastic packaging films. • Nanocellulose prepared from microcrystalline cellulose via green synthesis. • Green composite packaging films from PVA and lignocellulosic fiber of banana pseudostem (BPF) prepared. • Effect of nanocellulose on PVA–Banana pseudostem fiber (BPF) composite film. • Effect of nanocellulose on mechanical properties and water barrier properties is discussed. • Nanocellulose enhances tensile strength and water barrier property of PVA–BPF composite films.