Chitosan-based films reinforced with cellulose nanofibrils isolated from Euterpe oleraceae MART

2021 ◽  
Vol 12 (1-2) ◽  
pp. 46-59
Author(s):  
DG Braga ◽  
PGF Bezerra ◽  
ABFD Lima ◽  
HA Pinheiro ◽  
LG Gomes ◽  
...  

The use of local raw materials for the production of biodegradable films can simultaneously contribute to the development of the Amazon and global sustainability. This work aimed to evaluate the physical and mechanical performance of chitosan-based bionanocomposite films reinforced with different loads of cellulose nanofibrils obtained from açaí ( Euterpe oleraceae Mart.) under two nanofibrillation degrees. Nanofibrils were obtained by 3 and 21 passages in a grinder defibrillator. The films were produced by casting with nanofibril reinforcement at 5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%. The increase in the nanofibril level and nanofibrillation degree reduced water vapor absorption (75.20% to 51.93%), water solubility (28.33% to 17.91%), and density (0.87 g.cm−3 to 0.61 g.cm−3). The water vapor permeability decreased with higher nanofibril loads for both 3-pass (47.30% to 43.61%) and 21-pass (49.82% to 44.48%) reinforced films, but not with nanofibrillation degree. The increase in 3-pass nanofibril level decreased tensile strength (8.18 MPa to 7.88 MPa), modulus of elasticity (867.62 MPa to 670.02 MPa) and elongation at break (0.02 mm.mm−1 to 0.01 mm.mm−1). However, the opposite effect happened to 21-pass nanofibrils, with increases from 9.16 MPa to 9.73 MPa and from 502.00 MPa to 1119.62 MPa for tensile strength and modulus of elasticity, respectively. Meanwhile, the maximum elongation at rupture did not vary. It was concluded that chitosan-based bionanocomposite films reinforced with 20 wt.% of 21-pass nanofibril were more resistant, except for water vapor permeability. Adding coarser nanofibrils enhanced this property. The 3-pass nanofibrils reinforcement enables water solubility, which benefits other packaging applications.

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Thiago Moreira Cruz ◽  
Adriano Reis Prazeres Mascarenhas ◽  
Mário Vanoli Scatolino ◽  
Douglas Lamounier Faria ◽  
Lays Camila Matos ◽  
...  

Abstract 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.


Optimization of film formula-based kappa-carrageenan and polyvinyl alcohol (PVA) was studied using a two-level, two-factor Design Expert 11® by Response Surface Methodology (RSM) Central Composite Design (CCD). The aim of this study was to obtain the optimal concentration of kappa-carrageenan and polyvinyl alcohol in producing films. The influence composition ⱪ-carrageenan and polyvinyl alcohol was characterized. The results showed the effects of k-carrageenan and polyvinyl alcohol had a significant effect on the response thickness, tensile strength, burst strength, elongation, solubility, water vapor barrier, opacity, color, and moisture content. The optimized condition for production k-carrageenan and PVA was 1.21% carrageenan and 1.93% polyvinyl alcohol, which was giving film with thickness 0.044 mm, tensile strength 16.69 MPa, burst strength 167.86 kPa, elongation 81.79%, water solubility 65.04%, water vapor permeability 7.49 g/m s Pa x 10-11, opacity 2.31, ΔE 2.42, and moisture content 19.13%


Author(s):  
Grégoire David ◽  
Laurent Heux ◽  
Stéphanie Pradeau ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy

Abstract This paper aims at investigating the potential of vine shoots (ViSh) upcycling as fillers in novel poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) based biocomposites. ViSh particles of around 50 µm (apparent median diameter) were obtained combining dry grinding processes, and mixed with PHBV using melt extrusion. Thermal stability and elongation at break of biocomposites were reduced with increasing contents of ViSh particles (10, 20 and 30 wt%), while Young’s modulus and water vapor permeability were increased. It was shown that a surface gas-phase esterification allowed to significantly increase the hydrophobicity of ViSh particles (increase of water contact angles from 59° to 114°), leading to a reduction of 27% in the water vapor permeability of the biocomposite filled with 30 wt% of ViSh. The overall mechanical performance was not impacted by gas-phase esterification, demonstrating that the interfacial adhesion between the virgin ViSh particles and the PHBV matrix was already good and that such filler surface treatment was not required in that case. It was concluded that ViSh particles can be interestingly used as low cost fillers in PHBV-based biocomposites to decrease the overall cost of materials.


2000 ◽  
Vol 9 (1) ◽  
pp. 23-35 ◽  
Author(s):  
P. TANADA-PALMU ◽  
H. HELÉN ◽  
L. HYVÖNEN

Edible films from wheat gluten were prepared with various amounts of glycerol as a plasticizer. Water vapor permeability, oxygen permeability, tensile strength and percentage elongation at break at different water activities ( aw ) were measured. Films with low amounts of glycerol had lower water vapor and oxygen permeabilities, higher tensile strength and lower elongation at break. Wheat gluten coatings reduced weight loss during two weeks of storage for cherry tomatoes and sharon fruits compared to uncoated controls. A bilayer film of wheat gluten and beeswax significantly lowered weight loss from coated cheese cubes compared to single layer coating of wheat gluten.;


2021 ◽  
Vol 60 (1) ◽  
Author(s):  
Gema Morales-Olán ◽  
María Antonieta Ríos-Corripio ◽  
Aleida Selene Hernández-Cázares ◽  
Placido Zaca-Morán ◽  
Silvia Luna-Suárez ◽  
...  

Research background. Amaranth flour (Amaranthus hypochondriacus) produces films with excellent barrier properties against water vapor, allowing food preservation, but the mechanical properties are poor versus to synthetic films. One strategy to improve these properties is the incorporation of nanoparticles. The particles can also serve as a vehicle for the addition of antioxidants agents into the films. The objective of this work was to optimize the formulation for preparation of amaranth flour films treated with antioxidant chia (Salvia hispanica L.) extract-loaded chitosan particles using RSM. Experimental approach. Chitosan nanoparticles with the extract were synthesized by ionic gelation, and the films were made by the casting method. Three independent variables were assigned: amaranth flour (4-6 %), glycerol (25-35 %), and chitosan nanoparticles loaded with the chia extract (0-0.75 %). We then evaluated the physical (thickness), mechanical (tensile strength, Young´s modulus, and elongation), barrier (water vapor permeability, moisture, and water solubility), and antioxidant properties of the films. The experimental results of the properties were analyzed using a Box-Behnken experimental design generating 15 runs with three replicates at the central point. Results and conclusions. Second and third order polynomial models were obtained from the ANOVA analysis of the evaluated responses, and high coefficients of determination were found (0.91-1.0). The films presented a water vapor permeability of 0.82-2.39·10-7 (g·mm)/(Pa·s·m2), a tensile strength of 0.33-1.63 MPa, and antioxidant activity of 2.24-5.65 %. The variables had different effects on the films: The glycerol negatively affected their properties, and the permeability values increased with amaranth flour concentration. The nanoparticles improved the mechanical, barrier, and antioxidant properties of the films versus films without nanosystems. The optimal formulation was 4 % amaranth flour, 25 % of glycerol, and 0.36 % of chitosan nanoparticles. The optimized films had better mechanical (1.62 MPa) properties, a low water vapor permeability value (0.91·10-7 (g·mm)/(Pa·s·m2)), and moderate antioxidant activity (6.43 %). Novelty and scientific contribution. The results show the effect of chitosan nanoparticles on the properties of amaranth flour films for the first time. The resulting equations are useful in the design of food packaging.


Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 384
Author(s):  
Juan Tirado-Gallegos ◽  
Paul Zamudio-Flores ◽  
José Ornelas-Paz ◽  
Claudio Rios-Velasco ◽  
Guadalupe Olivas Orozco ◽  
...  

Apple starch films were obtained from apples harvested at 60, 70, 80 and 90 days after full bloom (DAFB). Mechanical properties and water vapor permeability (WVP) were evaluated. The apple starch films at 70 DAFB presented higher values in the variables of tensile strength (8.12 MPa), elastic modulus (3.10 MPa) and lower values of water vapor permeability (6.77 × 10−11 g m−1 s−1 Pa−1) than apple starch films from apples harvested at 60, 80 and 90 DAFB. Therefore, these films were chosen to continue the study incorporating ellagic acid (EA). The EA was added at three concentrations [0.02% (FILM-EA0.02%), 0.05% (FILM-EA0.05%) and 0.1% (FILM-EA0.1%) w/w] and compared with the apple starch films without EA (FILM-Control). The films were characterized by their physicochemical, optical, morphological and mechanical properties. Their thermal stability and antioxidant capacity were also evaluated. The FILM-Control and FILM-EA0.02% showed a uniform surface, while FILM-EA0.05% and FILM-EA0.1% showed a rough surface and insoluble EA particles. Compared to FILM-Control, EA modified the values of tensile strength, elasticity modulus and elongation at break. The antioxidant capacity increased as EA concentration did. EA incorporation allowed obtaining films with higher antioxidant capacity, capable of blocking UV light with better mechanical properties than film without EA.


2015 ◽  
Vol 4 (2) ◽  
pp. 103-14
Author(s):  
Gholamreza Kavoosi ◽  
Amin Shakiba ◽  
Mahmood Ghorbani ◽  
Seyed Mohammad Mahdi Dadfar ◽  
Amin Mohammadi Purfard

Background: Development of biodegradable and biocompatible films based on protein polymer with strong antioxidant and antibacterial activities has gradually obtained extensive concern in the world. In this study, the improvement of gelatin film properties incorporated with Ferula assa-foetida essential oil (FAO) as a potential antioxidant/antibacterial wound dressing film was investigated. Materials and Methods: Gelatin films were prepared from gelatin solutions (10% w/v) containing different concentration of FAO. The effect of FAO addition on water solubility, water swelling, water vapor permeability, mechanical behavior, light barrier properties as well as antioxidant and antibacterial activities of the films were examined. Results: Water solubility, water swelling and water vapor permeability for pure gelatin films were 29 ± 1.6%, 396 ± 8%, 0.23 ± 0.018 g.mm/m2.h, respectively. Incorporation of FAO into gelatin films caused a significant decrease in swelling and increase in solubility and water vapor permeability. Tensile strength, elastic modulus and elongation at break for pure gelatin films were 4.2 ± 0.4 MPa, 5.8 ± 4.2 MPa, 128 ± 8 %, respectively. Incorporation of FAO into gelatin films caused a significant decrease in tensile strength and elastic modulus and increase in elongation at break of the films. Gelatin film showed UV-visible light absorbance ranging from 280 to 480 nm with maximum absorbance at 420 nm. Gelatin/FAO films also exhibited excellent antioxidant ad antimicrobial activities. Conclusions: Our results suggested that gelatin/FAO films could be used as active films due to their excellent antioxidant and antimicrobial features for different biomedical applications including wound-dressing materials.[GMJ.2015;4(2):103-14]


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4406
Author(s):  
Anita Kwaśniewska ◽  
Michał Świetlicki ◽  
Adam Prószyński ◽  
Grzegorz Gładyszewski

In the present study, starch/powdered activated carbon composite films were prepared by incorporating various amounts of powdered activated carbon (PAC)—1–5, 10, and 15 %—into a starch matrix, using the solvent casting method. The effect of PAC addition on the biopolymer film was investigated. The mechanical properties were examined by ultra-nanoindentation, nanoscratch, and micro-tensile tests. Since the mechanical properties of biopolymer films are correlated with their structure, the effect of PAC addition was tested using X-ray diffraction. The surface parameters morphology and wettability were analyzed by atomic force microscopy (AFM) and contact angle measurements. The barrier properties were examined by determining water vapor permeability and the water solubility index. The obtained results did not show a monotonic dependence of the mechanical parameters on PAC content, with the exception of the maximum strain, which decreased as the amount of the additive increased. The visible effect of PAC addition was manifested in changes in the adhesive force value and in water vapor permeability (WVP). The barrier properties decreased with the increase of the filler content.


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