Biopolymer Nanocomposite Films Reinforced with Nanocellulose Whiskers

Abstract

A xylan nanocomposite film with improved strength and barrier properties was prepared by a solution casting using nanocellulose whiskers as a reinforcing agent. The 13 C cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) analysis of the spectral data obtained for the NCW/xylan nanocomposite films indicated the signal intensity originating from xylan-cellulose interactions. Qualitatively, the spectral data obtained for the NCW/xylan nanocomposite films indicated that the amount of xylan adsorbed to cellulose increases with the addition of NCW. In an attempt to quantify this effect, non-linear least-squared spectral line fitting was used to deconvolute the adsorbed xylan peak at ∼82 ppm. The peak intensity ratio of adsorbed xylan peak and xylan C 1 peak, which represents the total amount of xylan increases suggesting that upon the addition of NCW, the amount of adsorbed xylan increases. In an effort to further infer the structure-property relationships associated with the observed strength and barrier properties, 1 H NMR T 2 relaxation experiments were also conducted to investigate the change in the nature of carbohydrate-water interactions as a result of NCW incorporation. Water adsorbed into the 50% nanocomposite film had significantly shorter relaxation times with respect to the control xylan/sorbitol and all other NCW/xylan nanocomposite films. Additionally, X-ray diffraction of the nanocomposite films showed increased levels of crystalline material in the nanocomposites due to NCW addition.

Long-Term Physical Stability of Plasticized Hemicellulose Films

“…However, in that study, the OsAX used was from a different supplier. The crystallinity of 26% was also obtained by Saxena et al (2011) who studied OsAX films plasticized with 100% sorbitol (of the weight of the OsAX). In the present study the average size of single xylan crystallites in OsAX films was determined to be 5 to 10 nm.…”

Nanostructural Effects on Polymer and Water Dynamics in Cellulose Biocomposites: 2H and 13C NMR Relaxometry

“…Since NMR relaxation times are sensitive to molecular dynamics, there have been previous studies of water-lignocellulose systems as well as of water–polymer interactions in hydrogel polymers, , with 1 H NMR as the main experimental method. While valuable conclusions − are drawn both about microscopic and macroscopic features, only a few issues are definitely settled. A limitation of 1 H NMR as a molecular tool for water–polymer interaction studies is its poor ability to permit quantitative interpretation.…”

Research Progress in Hemicellulose-Based Nanocomposite Film as Food Packaging

“…Saxena and colleagues [ 105 ] prepared xylan/sorbitol composite film with good strength and barrier properties by using nanocellulose whisker (NCW) as the reinforcing agent. It was found that the X-ray diffraction peaks of xylan-NCW nanocomposite films changed from weak and broad peaks to sharp peaks with the increase in NCW content.…”