High Performance Cellulose Nanocomposites: Comparing the Reinforcing Ability of Bacterial Cellulose and Nanofibrillated Cellulose

Abstract

This work investigates the surface and bulk properties of nanofibrillated cellulose (NFC) and bacterial cellulose (BC), as well as their reinforcing ability in polymer nanocomposites. BC possesses higher critical surface tension of 57 mN m-1 compared to NFC (41 mN m-1). The thermal degradation temperature in both nitrogen and air atmosphere of BC was also found to be higher than that of NFC. These results are in good agreement with the higher crystallinity of BC as determined by XRD, measured to be 71% for BC as compared to NFC of 41%. Nanocellulose papers were prepared from BC and NFC. Both papers possessed similar tensile moduli and strengths of 12 GPa and 100 MPa, respectively. Nanocomposites were manufactured by infusing the nanocellulose paper with an epoxy resin using vacuum assisted resin infusion. The cellulose reinforced epoxy nanocomposites had a stiffness and strength of approximately ~8 GPa and ~100 MPa at an equivalent fibre volume fraction of 60 vol.-%. In terms of the reinforcing ability of NFC and BC in a polymer matrix, no significant difference between NFC and BC was observed.

Cellulose nanopapers as tight aqueous ultra-filtration membranes

“…The diameter of BC was found to be approximately 50 nm with fibril lengths of up to several micrometres [26]. Nanofibrillated cellulose was prepared by the mechanical grinding (MKZA10-15J Supermasscolloider, Masuko Sangyo Co., Kawaguchi, Japan) of chlorine free never-dried bleached birch kraft pulp (UPM-Kymmene Corporation, Pietarsaari, Finland) [19]. Herein, we termed this nanofibrillated cellulose as NFC-K.…”

“…The pulp was passed through the grinder seven times and the final consistency of the aqueous gel-like NFC-K was 1.8 wt.-%. NFC-K fibrils possess a fibrous structure with diameters of approximately 50 nm and lengths of up to several micrometres [19]. The carbohydrate composition of the pulp and the NFC produced from it are similar, consisting of 73 % glucose, 26 % xylose and 1 % mannose, respectively [27].…”

“…Nanocellulose (NFC) has gained considerable attention in recent years due to its outstanding mechanical and chemical properties [9,10], especially when used in composites [11,12]. Nanocellulose used in paper form, herein termed nanopapers, possesses excellent mechanical properties, low thermal expansion coefficients, high optical transparency and good gas barrier properties [13][14][15][16][17][18][19][20].…”

Correlation between cellulose thin film supramolecular structures and interactions with water

“…3 This has been explained by the high crystallinity of the fibrils (degree of crystallinity 40-60 % depending on the fibril source) and high density of the films. 17,18 However, the effect of cellulose crystallinity on interactions with water has not been discussed in detail. Furthermore, the influence of porosity on film strength has been determined 19 but film porosity has not been directly correlated with permeability or with molecular interactions in the presence of water.…”

Nanocellulose in Thin Films, Coatings, and Plies for Packaging Applications: A Review

“…A patent by Schade et al (2015) lists a "curing agent" as an option to cure a nanocellulose-reinforced film in the course of its extrusion. Curable resins such as epoxy also have been impregnated into pre-formed cellulosic films (Lee et al 2012) Pre-milling and pre-mixingAs a way to improve the performance of extrusion operations, efforts to improve the initial blending of ingredients can be important. Ambrosio-Martin et al (2015b) used ball milling to improve the incorporation of freeze-dried CNC aggregates in a more fully dispersed form.…”