Processing and properties of eco-friendly bio-nanocomposite films filled with cellulose nanocrystals from sugarcane bagasse

Abstract

Novel synthesis strategy of eco-friendly bio-nanocomposite films have been exploited using cellulose nanocrystals (CNC) and polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) blend matrix as a potential in food packaging application. The CNC were extracted from sugarcane bagasse using sulfuric acid hydrolysis, and they were successfully characterized regarding their morphology, size, crystallinity and thermal stability. Thereafter, PVA/CMC-CNC bio-nanocomposite films, at various CNC contents (0.5-10wt%), were fabricated by the solvent casting method, and their properties were investigated. It was found that the addition of 5wt% CNC within a PVA/CMC increased the tensile modulus and strength by 141% and 83% respectively, and the water vapor permeability was reduced by 87%. Additionally, the bio-nanocomposites maintained the same transparency level of the PVA/CMC blend film (transmittance of ∼90% in the visible region), suggesting that the CNC were dispersed at the nanoscale. In these bio-nanocomposites, the adhesion properties and the large number of functional groups that are present in the CNC's surface and the macromolecular chains of the PVA/CMC blend are exploited to improve the interfacial interactions between the CNC and the blend. Consequently, these eco-friendly structured bio-nanocomposites with superior properties are expected to be useful in food packaging applications.

Reuse of red algae waste for the production of cellulose nanocrystals and its application in polymer nanocomposites

“…Meanwhile, the elongation at break was reduced to 41.72 %, which corresponds to a 54 % decrease in comparison with neat PVA (90.07 %). This is also observed in a variety of previously reported CNC filled polymer nanocomposite, which is related to the reinforcing ability of rigid nanoparticles [23,24,29].…”

“…From these data, it could be seen that all nanocomposites containing CNC exhibited superior tensile properties than those observed for neat PVA polymer, thus confirming that the addition of CNC has a positive effect on the improvement of the nanocomposite films' tensile properties. [23,24,29]. Meanwhile, the elongation at break was reduced to 41.72 %, which corresponds to a 54 % decrease in comparison with neat PVA (90.07 %).…”

“…Indeed, the % S measured for CNC30, CNC40 and CNC80 was found to be 1.23 %, 1.47 % and 1.95 %, respectively, showing a proportionality between the zeta potential value and the amount of % S. All the obtained suspensions can be considered stable since the absolute value is greater than 25 mV [31]. Indeed, the good stability is caused by the exclusion of the polar components, the insertion of polar sulfate groups upon acid hydrolysis, and the exposure of the -OH groups from the cellulosic structure [29].…”

“…CNC were successfully extracted from AW by alkali and bleaching treatments followed by an acid hydrolysis process, as described in our previous works [23,24,29]. The as-received AW samples were first cut into small pieces (≤ 2 cm), which were ground using a precision grinder …”

Hydrogen‐bonding assembly of heteropolyacid and poly(vinyl alcohol) for strong, flexible, and transparent UV‐protective films

“…Figure displays the typical TGA and relevant DTG curves of pure SiMoA, PVA and PVA/SiMoA composites. A small mass loss occurring at approximately 100 °C can be observed in all samples, which is attributed to the removal of the moisture . For SiMoA, the DTG curve in Figure (b) presents a distinct mass loss at about 500 °C, which should be attributed to the thermal degradation of SiMoA .…”