scholarly journals Improved Process to Obtain Nanofibrillated Cellulose (CNF) Reinforced Starch Films with Upgraded Mechanical Properties and Barrier Character

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1071 ◽  
Author(s):  
Luis Angel Granda ◽  
Helena Oliver-Ortega ◽  
Maria José Fabra ◽  
Quim Tarrés ◽  
Maria Àngels Pèlach ◽  
...  
Keyword(s):  
Composite Films ◽  
High Capacity ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Thermoplastic Starch ◽  
Nanofibrillated Cellulose ◽  
Vapor Permeability ◽  
The Matrix ◽  
Starch Films ◽  
The One

Nowadays, the interest on nanofibrillated cellulose (CNF) has increased owing to its sustainability and its capacity to improve mechanical and barrier properties of polymeric films. Moreover, this filler shows some drawbacks related with its high capacity to form aggregates, hindering its dispersion in the matrix. In this work, an improved procedure to optimize the dispersability of CNF in a thermoplastic starch was put forward. On the one hand, CNF needs a hydrophilic dispersant to be included in the matrix, and on the other, starch needs a hydrophilic plasticizer to obtain a thermoformable material. Glycerol was used to fulfil both targets at once. CNF was predispersed in the plasticizer before nanofibrillation and later on was included into starch, obtaining thin films. The tensile strength of these CNF–starch composite films was 60% higher than the plain thermoplastic starch at a very low 0.36% w/w percentage of CNF. The films showed a noticeable correlation between water uptake, and temperature and humidity. Regarding permeability, a ca. 55% oxygen and water vapor permeability drop was found by nanofiller loading. The hydrolytic susceptibility of the composite was confirmed, being similar to that of the thermoplastic starch.

scholarly journals Preparation and Properties of Corn Starch/Chitin Composite Films Cross-Linked by Maleic Anhydride

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1606
Author(s):  
Peng Yin ◽  
Jinglong Liu ◽  
Wen Zhou ◽  
Panxin Li
Keyword(s):  
Maleic Anhydride ◽  
Corn Starch ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Contact Angles ◽  
Vapor Permeability ◽  
Water Contact ◽  
Elongation At Break ◽  
Shrimp Shell ◽  
Starch Films

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films.

scholarly journals Packaging Composite Films Fabricated from Cellulose Pulp with Polyurethane and Curcumin by Using NMMO ionic Liquid Solvent

2021 ◽  
Author(s):  
Chaehyun Jo ◽  
Sam Soo Kim ◽  
Srinivasan Ramalingam ◽  
Prabakaran D. S ◽  
Balasubramanian Rukmanikrishnan ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Cost Effective ◽  
Barrier Properties ◽  
Vapor Permeability ◽  
Visual Appearance ◽  
Cellulose Pulp ◽  
Cost Effective Method ◽  
Uv Transmittance

Abstract Cellulose pulp (CP), polyurethane (PU), and curcumin-based biocompatible composite films were prepared using a simple cost-effective method. These materials dissolved well in the ionic liquid solvent N-methylmorpholine N-oxide. Significant structural and microstructural changes were observed in CP upon the addition of PU. These changes were studied using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The 5% and 10% gravimetric losses of the CP/PU/curcumin composite were found to be in the range 87.2–182.3 ºC and 166.7–249.8 ºC, respectively. The addition of PU significantly improved the thermal stability and water barrier properties of the composites. All the composites exhibited single Tg values in the range 147.4–154.2 ºC. The tensile strength of CP was measured to be 93.2 MPa, which dropped to 14.1 MPa for the 1:0.5 CP/PU composite and then steadily increased to 30.5 MPa with further addition of PU. The elongation at break of the composites decreased from 8.1 to 3.7% with the addition of PU. The addition of PU also improved the water vapor permeability (3.96 ×10–9 to 1.75 ×10–9 g m–1 s–1 Pa–1) and swelling ratio (285 to 202%) of the CP composite films. The CP/PU/curcumin composite exhibited good antioxidant activity and no cytotoxicity when tested on the HaCat cell line. The visual appearance and UV transmittance (86.2–32.9% at 600 nm) of the CP composite films were significantly altered by the incorporation of PU and curcumin. This study demonstrates that CP/PU/curcumin composites can be used for various packaging and biomedical applications.

scholarly journals Physical Properties of Starch/Powdered Activated Carbon Composite Films

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4406
Author(s):  
Anita Kwaśniewska ◽  
Michał Świetlicki ◽  
Adam Prószyński ◽  
Grzegorz Gładyszewski
Keyword(s):  
Mechanical Properties ◽  
Activated Carbon ◽  
Water Vapor ◽  
Water Solubility ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Carbon Composite ◽  
Powdered Activated Carbon ◽  
Vapor Permeability

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.

Mechanical and Physical Properties of Soy Protein Films with pH-Modified Microstructures

2008 ◽  
Vol 14 (2) ◽  
pp. 119-125 ◽  
Author(s):  
A.N. Mauri ◽  
M.C. Añón
Keyword(s):  
Soy Protein ◽  
Disulfide Bonds ◽  
Mechanical Test ◽  
Soy Protein Isolate ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Protein Isolate ◽  
Vapor Permeability ◽  
Protein Films ◽  
The One

Mechanical, physical, and barrier properties of films obtained from soy protein isolate solutions at different pH were studied and correlated with the structural properties and the microstructure of films. Films obtained at pH 2 and 11, which had denser microstructures and a higher amount of disulfide bonds, showed a higher tensile strength — of about 1.05 MPa — and a higher Young's modulus — of at least 0.15MPa — than the one at pH 8. However, films formed at alkaline pH (8 and 11) exhibited a higher deformation than films at pH 2 — by about 70%. The presence of at least a protein fraction in native state allowed macromolecules to unfold during the mechanical test, reaching greater deformation before breaking. Acidic films exhibited higher water vapor permeability — of about 7 × 10-11 g/m s Pa — and water content — of about 1.5% — and a lower glass transition temperature — of at least 15 °C — than basic ones, due to their higher hydrophilic nature.

Biodegradable green composite film developed from Moringa Oleifera (Sahajana) seed filler and PVA: Surface functionalization, characterization and barrier properties

2021 ◽  
pp. 089270572110075
Author(s):  
Kajal Mishra ◽  
Shishir Sinha
Keyword(s):  
Composite Film ◽  
Surface Functionalization ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Vapor Permeability ◽  
Green Composite ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force

The present work focuses on surface functionalization, characterization, biodegradability and barrier properties of MOSF as a practicable reinforcement in PVA matrix. Film-forming dispersions at different concentrations of alkali and acid treatments were casted at room temperature. The effect of surface modifications on the developed film’s compositional, physical, mechanical, biodegradability and barrier properties were analyzed. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) were used to describe the functional composition, formation and surface morphology of the film. The 5% acid treated film significantly increases the tensile strength (33.69 MPa) and flexural strength (56.612 MPa), which was close to the frequently used LDPE and HDPE package films. Composite films were moisture absorptive but simultaneously capable to maintain uniformity and composition upon modifications. Lower water vapor permeability (1.42 × 10−10gs−1 m−1 Pa−1), eminent biodegradability proved the suitability of composite film for various packaging applications.

scholarly journals The Role of Structure and Interactions in Thermoplastic Starch–Nanocellulose Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3186
Author(s):  
Emília Csiszár ◽  
Dávid Kun ◽  
Erika Fekete
Keyword(s):  
Composite Films ◽  
Water Vapor Permeability ◽  
High Water ◽  
Thermoplastic Starch ◽  
Vapor Permeability ◽  
Visible Spectroscopy ◽  
Different Types ◽  
Additional Water ◽  
Human Eyes

Composite films were fabricated by using cellulose nanocrystals (CNCs) as reinforcement up to 50 wt% in thermoplastic starch (TPS). Structure and interactions were modified by using different types (glycerol and sorbitol) and different amounts (30 and 40%) of plasticizers. The structure of the composites was characterized by visible spectroscopy, Haze index measurements, and scanning electron microscopy. Tensile properties were determined by tensile testing, and the effect of CNC content on vapor permeability was investigated. Although all composite films are transparent and can hardly be distinguished by human eyes, the addition of CNCs somewhat decreases the transmittance of the films. This can be related to the increased light scattering of the films, which is caused by the aggregation of nanocrystals, leading to the formation of micron-sized particles. Nevertheless, strength is enhanced by CNCs, mostly in the composite series prepared with 30% sorbitol. Additionally, the relatively high water vapor permeability of TPS is considerably decreased by the incorporation of at least 20 wt% CNCs. Reinforcement is determined mostly by the competitive interactions among starch, nanocellulose, and plasticizer molecules. The aging of the films is caused by the additional water uptake from the atmosphere and the retrogradation of starch.

scholarly journals Production of starch/poly(lactic acid) sheets containing citric acid and tributyl citrate

2016 ◽  
Vol 7 (2) ◽  
pp. 173 ◽  
Author(s):  
Silvio José Souza ◽  
Nicolli Grecco Marchiore ◽  
Marcella Vitória Galindo ◽  
Fabio Yamashita ◽  
Marianne Ayumi Shirai
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Citric Acid ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Water Vapor Barrier

In this work thermoplastic starch and poly(lactic acid) (PLA) sheets added of tributyl citrate (TBC) and citric acid was produced by flat extrusion (calendaring-extrusion). The incorporation of TBC and citric acid reduced the rigidity, increased the water vapor permeability (WVP) and density of the sheets. This occurred probably because these compounds acted as plasticizer for PLA and starch. Thus, it was possible to conclude that it was possible to produce starch and PLA blended sheets by extrusion, but studies are still required to find the appropriate concentration of TBC and citric acid that does not significantly impair the water vapor barrier properties.

scholarly journals Preparation, Properties and Mechanism of Anionic and Cationic CNC/WPU Composite Films

2021 ◽  
Author(s):  
Ya-Yu Li ◽  
Yan-Ru Bai ◽  
Xin-Qian Zhang ◽  
Xin Liu ◽  
Zhen Dai ◽  
...  
Keyword(s):  
Composite Film ◽  
Food Packaging ◽  
Composite Films ◽  
Interaction Mechanism ◽  
Water Vapor Permeability ◽  
Waterborne Polyurethane ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
Vapor Permeability

Abstract Three kinds of cellulose nanocrystals (CNCs) were added into waterborne polyurethane (WPU), and nanocomposite films were prepared by solution casting method. The influence of different ionic function groups on microstructure and properties of composite films was investigated, and interaction mechanism between these two components was analyzed. Results show that thermal stability of these composite films are improved by 15℃. Compared with sulfated CNCs （SCNCs） and TEMPO oxidized CNCs (TOCNCs), FE-SEM results prove that cationized CNCs (CaCNCs) have better dispersion in composite films. In addition, fracture surface did not display large cavities, which indicates the interface binding force between WPU and CaCNCs is stronger. The tensile strength and fracture work of CaCNC/WPU composite film increase by 11.9% and by 8.4%, respectively. The oxygen permeability of CaCNC/WPU composite film is the lowest in these composite films, which is 5.00 cm3•cm (cm2•s•Pa)-1. Water vapor permeability of composite films may have a close positive correlation with their hygroscopicity. In all, composite film with CaCNCs has optimal strength, toughness, light transmittance and oxygen barrier properties. There may be opposite ion attraction superimposed hydrogen bond between CaCNCs and WPU in the composite film. The composite films are expected to have applications in food packaging, furniture coatings and biomedical applications.

Mechanical and Water Barrier Properties of Zein–Corn Starch Composite Films as Affected by Gallic Acid Treatment

2016 ◽  
Vol 12 (8) ◽  
pp. 773-781 ◽  
Author(s):  
Kingsley Masamba ◽  
Yue Li ◽  
Hafiz Rizwan Sharif ◽  
Jianguo Ma ◽  
Fang Zhong
Keyword(s):  
Composite Film ◽  
Gallic Acid ◽  
Acid Treatment ◽  
Corn Starch ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Vapor Permeability ◽  
Water Barrier ◽  
Film Forming

Abstract The effect of gallic acid treatment on mechanical and water barrier properties in zein and zein–corn starch composite films was investigated. Four concentrations of corn starch (5 %, 10 %, 15 %, 20 %) were used in composite films making a final solid concentration of 6 % (w/v) in the film forming solution. One composite film containing 10 % corn starch was also prepared in absence of gallic acid for comparison purpose. Gallic acid treatment improved tensile strength (TS) and water vapor permeability (WVP) while solubility was increased in control zein films. On the other hand, gallic acid treatment significantly (p < 0.05) reduced TS and increased WVP in zein–corn starch composite films. Interestingly, mechanical and water barrier properties of composite films prepared in absence of gallic acid were comparatively better than gallic acid treated composite films. These findings provided useful insights in how each individual hydrocolloid in the composite film was differently affected by gallic acid treatment.

Effect of the talc filler on structural, water vapor barrier and mechanical properties of poly(lactic acid) composites

2016 ◽  
Vol 36 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Aleksandra Buzarovska ◽  
Gordana Bogoeva-Gaceva ◽  
Radek Fajgar
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Water Vapor ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Scanning Calorimetry ◽  
Structural Water

Abstract Poly(lactic acid) (PLA) based composite films with different content of talc (5–15 wt%) were prepared by the solvent casting method. The effect of talc on morphological, structural, thermal, barrier and mechanical properties of neat PLA was investigated. The PLA/talc composites revealed a polymorphic crystalline structure, as demonstrated by X-ray diffraction (XRD) study and differential scanning calorimetry (DSC) analysis. The PLA/talc composites also exhibited significantly improved barrier properties (up to 55% compared to neat PLA), as shown by water vapor permeability (WVP) tests. The puncture measurements showed improved mechanical properties at lower content of talc (up to 5 wt%), and increased brittleness of the PLA/talc composite films at higher talc concentrations.

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