The effect of nanocellulose on mechanical and physical properties of chitosan-based biocomposites

Abstract

The effect of two types of nanocellulose on the mechanical properties of chitosan (CH) film was examined in terms of elongation, tensile strength, and dynamic-mechanical properties such as tan δ and storage modulus. Chitosan films were reinforced by cellulose nanocrystal (CNC) and cellulose nanofiber (CNF) with different ratios. CH/CNC and CH/CNF nanocomposite films containing 0–7 wt.% nanofibers were produced by solution casting. A comparison between CNC and CNF was made based on their nanostructures and interfacial bonding with the CH matrix. For both CNC and CNF, reinforcing effects in nanocomposite polymer films were presented. The results demonstrated that nanocomposite films can increase mechanical properties; 7 wt.% CNF and CNC had the most increasing effect on the mechanical properties, raising the tensile strength of the chitosan film by 104% and 52%, respectively. Moreover, the values of CH/CNC and CH/CNF films showed higher storage modulus compared to the pure chitosan film. CNF shows higher modulus and strength compared with CNC at the same amount of fiber because of CNFs’ percolation networks and their larger aspect ratio. Morphological studies revealed the dispersion of CNC and CNF is in the contiguous matrix of chitosan with a homogeneous distribution without agglomeration. The results also illustrated that CNC and CNF can improve the water resistance of chitosan films. The mechanical properties of composite films were acceptable to use as artificial skin and wound dressings.

Preparation of spherical nanocellulose from Gai bamboo and mechanical properties of chitosan/nanocellulose composite

“…Simultaneously with the increase of TS, the EB of the films also increased indicating the effectively dispersion of small‐sized CNCs throughout the CS substrate, resulting in a strong surface interaction with high bond strengths that became efficient loading sites. [ 18,29,37 ] Generally, the improvement in the stretchability of the film implied a reduced stress load at the interface between the two phases, thereby minimizing the compression in high‐stress areas. Hence, in most cases, the increase of EB led to reduce TS and vice versa as reported in the literature.…”

“…The similar increase of TS (till 52%) was reported by loading 7 wt% of rod-like CNCs. [18] Simultaneously with the increase of TS, the EB of the films also increased indicating the effectively dispersion T A B L E 3 Thermogravimetric analysis (TGA) results of raw bamboo fiber (BF), nanocellulose (56TP45), chitosan (CTC0), and CS reinforced CNCs 2 phr (CTC2)…”

“…Regarding to a role of CNCs as a potential high quality nanofillers to improve the mechanical and barrier properties of biopolymers, the incorporation of CNCs into chitosan (CS) matrix has been extensively investigated due to the compatibility between CNCs and CS (they are both categorized in polysaccharide). [6,[18][19][20][21][22][23][24] In addition, CS/CNCs bionanocomposites exhibit remarkable features such as biocompatible, biodegradable, non-toxic, renewable, and functionality. [25,26] These characteristics lead to a broad range of potential applications for CS/CNCs nanocomposite from biomedical, packaging to agricultural and environmental applications.…”

“…[25][26][27] In the literature, the limitations of CS such as fragility, chemical stability, and low barrier properties have been effectively overcome by reinforcing CNCs. For example, Tabeli et al [18] reported the increase of mechanical properties and the water resistance of CS reinforced CNCs. They explored the effect of CNCs shape including the nanofiber and rod-like structure on the improvement of mechanical properties of CS/CNCs and concluded that nanofibers were more effective than rod-like CNCs in enhancement the tensile strength (TS) and elongation at break (EB) of CS/CNCs.…”

Comparative analysis of cellulose nanocrystals and cellulose nanofibrils on the physico‐chemical properties of polyvinyl alcohol/chitosan blend for sustainable food packaging

“…Hence, CNCs are highly crystalline. Their dimensions are 10–20 nm in diameter and 100–500 nm in length, depending on the cellulose sources 16 . CNFs are often derived from the cellulose fibers by a mechanical process, while retaining their crystalline and amorphous phase 17 .…”