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In order to evaluate the influence of a different assembly of biocomposites of polyvinyl alcohol (PVOH), whey protein isolates (WPI), and nano-silica (NS), a bilayer film treated with corona discharge was produced through a two-step lamination. The first layer of PVOH/NS, treated with up to 90 s of discharge, and the second layer of WPI/NS, the bilayer films had their morphology, tensile strength, and water barrier investigated and compared to a single layer PVOH/WPI/NS film. Corona discharge increased the wettability of the first layer, improving the ability to interact with the second layer, thus increasing the adherence between these layers. Films treated with higher times of discharge showed a homogeneous transition between phases, suggesting compatibility, and adherence between layers. At 90 s of corona discharge treatment, bilayer films showed a tensile strength 72% higher than the bilayer film not treated and also 23% more resistant and 7.4 times more ductile than the single-layer film. The lamination process and corona treatment increase the affinity of water with film constituents, thus leading to a higher permeability. The use of corona discharge associated with the lamination of PVOH/WPI/NS biocomposites provides a bilayer film and produces a more resistant, flexible, and ductile biocomposite film for packaging. KEYWORDS bilayer packaging film, biocomposite, Corona discharge, nano-silica, polyvinyl alcohol, whey protein isolate, 1 | INTRODUCTION One of the biggest markets for plastics is that of packaging, which is projected to grow at a compound annual growth rate of 4.2% from 2021 to [...]

Typical scanning electron microscopy (SEM) micrographs obtained for cellulose nanofibrils (a), paper handsheets surface without CNF addition (b) and with 10% CNF (c) Cellulose nanofibrils used as reinforcement go through the fibrillation process in equipment that have discs with grooves on the surfaces against which the pulp is exposed to cyclical and sequential stresses. Preparation of paper handsheets (fiber/CNF) CNF were added directly to the cellulose pulp at 0, 2, 5, 8 and 10 wt% proportion before forming the paper handsheets. Box-plot for tensile index (a), tearing index (b), bursting index (c), stretch (d) and modulus of elasticity (e) in paper handsheets with the addition of different amounts of nanofibrils Figure 6 shows the variations of tensile (a), tearing (b), and bursting (c) indexes, and stretch (d) and modulus of elasticity (e) of cellulose paper handsheets due the addition of different CNF contents. Keywords: Composite fibers; kraft paper; mechanical properties; cellulose microfibrils (CMF); nanocellulose; papermaking; ; ; ; (CMF); ; EN Composite fibers kraft paper mechanical properties cellulose microfibrils (CMF) nanocellulose papermaking ZH (CMF) 7818 7833 16 11/21/22 20221220 NES 221220 GRAPHICAL ABSTRACT Graph Introduction Cellulose nanofibrils (CNF) or cellulose microfibrils (CMF) are known to present unique properties such as high strength and stiffness and to enable numerous applications such as reinforcement material in composites and paper (Osong, Norgren, and Engstrand [21]). [Extracted from the article]

The accumulation of petroleum polymers compromises biodiversity and causes environmental problems. Nanocellulose enhances biodegradability and can improve the physical-mechanical performance of materials. The objective was to produce and characterize hybrid films composed of bacterial cellulose (BC) and plant nanocellulose from Eucalyptus (Euc) or Pinus (Pin). Films were produced by the casting method using filmogenic suspensions with different cellulose nanofibrils (CNFs) proportions from both the sources (0, 25, 50, 75 and 100 %). CNFs suspensions were characterized by transmission electron microscopy. The morphology of the films was analyzed using scanning electron microscopy. In addition, the transparency, contact angle, wettability, oil and water vapor barrier and mechanical properties were also evaluated. The contact angles were smaller for films with BC and the wettability was greater when comparing BC with plant CNFs (0.10 ° s − 1 {\text{s}^{-1}} for 75 % Euc/25 % BC and 0.20 ° s − 1 {\text{s}^{-1}} for 25 % Euc/75 % BC). The water vapor permeability (WVP) of the 100 % BC films and the 25 % Euc/75 % BC composition were the highest among the studied compositions. Tensile strength, Young's modulus and puncture strength decreased considerably with the addition of BC in the films. More studies regarding pre-treatments to purify BC are needed to improve the mechanical properties of the films. [ABSTRACT FROM AUTHOR]