Reinforcement of poly (vinyl alcohol) films with alpha-chitin nanowhiskers

Abstract

Composites Films were produced using Poly (Vinyl Alcohol) as the soft material and reinforced with Chitin Nanowhiskers(NWCH) as the rigid material. The present work studies the reinforcing mechanisms of NWCH in PVA films, made through a solvent casting technique and characterized for their calorimetric, swelling and mechanical properties. DSC tests revealed a sharp increase of 45 °C in glass transition temperatures with only 1.5% NWCH, while melting temperature had a small increases suggesting an anti-plasticizing effect. Swelling tests revealed decreasing hygoscopy when NWCH volume fraction increases. Estimates for elastic tensile modulus using a model that predicts the formation of a percolating network were not consistent with the experimental data of tensile tests suggesting that contrary to the reinforcement with cellulose nanowhiskers the percolating network is not primarily responsible for the reinforcement of the films. By adjusting the Halpin-Tsai equations, modified by Nielsen it was found that the mechanical properties were mainly influenced by the packing of the NWCH.

Green Fabrication of High-Performance Chitin Nanowhiskers/PVA Composite Films with a “Brick-and-Mortar” Structure

“…As a rigid whisker-shaped nanomaterial, ChNWs are an ideal candidate for preparing nanocomposites as stiffeners to reinforce different polymer matrices. There are quite a few literatures reported using PVA and ChNWs as the raw materials for preparing nanocomposite films. − However, all these researches are focusing on preparing PVA-based composite films with ChNWs as the reinforcement filler with a ChNW content in composite film generally lower than 10 wt %. Composite film using ChNWs as the essential component rather than a reinforcement filler is rarely reported.…”

Cellulose Nanocrystals (CNCs) Induced Crystallization of Polyvinyl Alcohol (PVA) Super Performing Nanocomposite Films

“…PVA‐based nanocomposite materials are used in a wide range of industrial applications, including paper coatings, filtration membranes, thermoplastic packaging films, and more . Combination of reinforcing agents such as carbon nanotubes, cellulose nanofibers (NFC), and chitin has been shown to improve the mechanical and physical properties of the low mechanical strength PVA . The amorphous polymer chains of PVA, which are rich in hydroxyl groups, can interact and form strong hydrogen bonds with the highly crystalline hydrophilic surface of CNC, while preparation of nanocomposites based on CNC and PVA matrices has already been reported .…”

Isolation of Chitin Nano-whiskers Directly from Crustacean Biomass Waste in a Single Step with Acidic Ionic Liquids

“…Hence, ChNWs have emerged as novel nanomaterials with unique properties, with the most important application as thermoplastic/thermoset reinforcement material . The examples include reinforcement of poly­(vinyl alcohol) (PVA), − poly­(styrene- co -butyl acrylate) (poly­( S - co -BuA), biobased polymers such as PLA and PHA, , acrylonitrile-butadiene (NRB), polycaprolactone (PCL), , poly­(acrylic acid), polypropylene, and so forth. ChNWs are also used as nanosized fillers into thermoplastic/thermoset composites, as barrier property modifiers, and for the preparation of bioplastic films, biomedical nanomaterials, flexible packaging coatings, and multiple other applications.…”