scholarly journals Physical-Mechanical Behavior and Water-Barrier Properties of Biopolymers-Clay Nanocomposites

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6734
Author(s):  
Heidy Lorena Calambas ◽  
Abril Fonseca ◽  
Dayana Adames ◽  
Yaneli Aguirre-Loredo ◽  
Carolina Caicedo
Keyword(s):  
Barrier Properties ◽  
Polymeric Matrix ◽  
Clay Nanocomposites ◽  
Solvent Casting ◽  
Biodegradable Films ◽  
Elongation At Break ◽  
Biodegradable Packaging ◽  
Magnetic Stirring ◽  
The Matrix

The preparation and characterization of biodegradable films based on starch-PVA-nanoclay by solvent casting are reported in this study. The films were prepared with a relation of 3:2 of starch:PVA and nanoclay (0.5, 1.0, and 1.5% w/v), and glycerol as plasticizer. The nanoclays before being incorporated in the filmogenic solution of starch-PVA were dispersed in two ways: by magnetic stirring and by sonication. The SEM results suggest that the sonication of nanoclay is necessary to reach a good dispersion along the polymeric matrix. FTIR results of films with 1.0 and 1.5% w/v of sonicated nanoclay suggest a strong interaction of hydrogen bond with the polymeric matrix of starch-PVA. However, the properties of WVP, tensile strength, percentage of elongation at break, and Young’s modulus improved to the film with sonicated nanoclay at 0.5% w/v, while in films with 1.0 and 1.5% w/w these properties were even worse than in film without nanoclay. Nanoclay concentrations higher than 1.0 w/v saturate the polymer matrix, affecting the physicochemical properties. Accordingly, the successful incorporation of nanoclays at 0.5% w/v into the matrix starch-PVA suggests that this film is a good candidate for use as biodegradable packaging.

scholarly journals Physical-Mechanical Behavior and Water-Barrier Properties of Biopolymers-Clay Nanocomposites

2021 ◽  
Author(s):  
Heidy Lorena Calambas ◽  
Abril Fonseca ◽  
Dayana Adames ◽  
Yaneli Aguirre-Loredo ◽  
Carolina Caicedo
Keyword(s):  
Mechanical Properties ◽  
Barrier Properties ◽  
Clay Nanocomposites ◽  
Solvent Casting ◽  
New Materials ◽  
Vapour Permeability ◽  
Biodegradable Packaging ◽  
The Matrix ◽  
Response To Water

The preparation of new materials based on starch for the development of biodegradable packaging is increasing, however, the poor properties of this biopolymer for this application causes an area of opportunities for the improvement of water vapour permeability (WVP), mechanical properties, thermal properties, hydrophilicity, water absorption, among others. Hence, starch has been combined with other polymers such as polyvinyl alcohol, which has shown an improvement in the mechanical properties of starch, also, the use of clays suggests that the properties of response to water can be improved. Therefore, in this work, the preparation and characterization of starch-PVA-nanoclay films prepared by solvent casting is reported. The results obtained suggest that the sonication of nanoclay is necessary to reach a good dispersion, which promotes a strong interaction among starch-PVA-nanoclay. In addition, the properties of WVP and mechanical properties of films improved with incorporation of nanoclay, the concentration of 0.5% w/v of nanoclay showed to be the best concentration due to concentrations of 1.0 and 1.5% w/v were poorer than 0.5% w/v. Accordingly, the successful incorporation of nanoclays into the matrix starch-PVA suggests that this material is a good candidate for use as packaging.

Permeability of Polymer/Clay Nanocomposites

2011 ◽  
Vol 1312 ◽  
Author(s):  
Georgios A. Choudalakis ◽  
Alexandros D. Gotsis
Keyword(s):  
Free Volume ◽  
Diffusion Length ◽  
Volume Fraction ◽  
Interfacial Area ◽  
Barrier Properties ◽  
Polymeric Matrix ◽  
Nanocomposite Coatings ◽  
Clay Nanocomposites ◽  
The Matrix ◽  
Diffusion Mechanisms

ABSTRACTBecause of their large interfacial area, the presence of nanoplatelets in the polymeric matrix decelerates the process of diffusion of gases through the material. The particles are impermeable barriers to the diffusing molecules, forcing them to follow complicated paths, increasing, thus, the diffusion length. The barrier properties of the nanocomposites depend on the properties of the polymeric matrix, the volume fraction of the nanoplatelets, their aspect ratio, their orientation, and their interactions with the matrix. The mobility of the molecules is hindered by the crystallinity but it is facilitated by the free volume within the material. The size and shape of the free volume holes in the polymer affect, thus, the rate of diffusion. Interactions between the nanoparticles and the matrix may lower the barrier properties because they may increase the free volume in the material. The estimation of free volume in the nanocomposite is important for the proper choice of components and the manufacturing of nanocomposite coatings with optimum barrier properties. Detailed information about the diffusion mechanisms at atomic and molecular levels can be obtained using the approach of free volume.

scholarly journals Development and characterization of probiotic mucilage based edible films for the preservation of fruits and vegetables

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mohammad Davachi ◽  
Neethu Pottackal ◽  
Hooman Torabi ◽  
Alireza Abbaspourrad
Keyword(s):  
Fruits And Vegetables ◽  
Uv Light ◽  
Barrier Properties ◽  
Edible Films ◽  
Food Preservation ◽  
Elongation At Break ◽  
The Public ◽  
Medical Benefits ◽  
Seed Mucilage

AbstractThere is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.

Preparation and Characterization of Starch/PVA Blend for Biodegradable Packaging Material

2010 ◽  
Vol 123-125 ◽  
pp. 351-354 ◽  
Author(s):  
Fahmida Parvin ◽  
Md. Arifur Rahman ◽  
Jahid M.M. Islam ◽  
Mubarak A. Khan ◽  
A.H.M. Saadat
Keyword(s):  
Mechanical Properties ◽  
Packaging Material ◽  
Rice Starch ◽  
Packaging Materials ◽  
Casting Method ◽  
Environment Friendly ◽  
Elongation At Break ◽  
Biodegradable Packaging ◽  
Soil And Water

Polymer films of rice starch/Polyvinyl alcohol (PVA) were prepared by casting method. Different blends were made varying the concentration of rice starch and PVA. Tensile strength (TS) and elongation at break (Eb) of the prepared films were studied. Films made up of rice starch and PVA with a ratio of 2:8 showed highest TS. 10% sugar was added with highest TS giving four composition of Starch/PVA blend in order to increase TS and Eb. Films made up of rice starch and PVA and sugar with a ratio of 1:8:1 showed highest TS and Eb and the recorded value was 14.96MPa and 637% respectively. The physico-mechanical properties of the prepared sugar incorporated films were improved by grafting with acrylic monomer with the aid of UV radiation. A formulation was prepared with monomer, methylmethacrylat in methanol, and a photo initiator. The highest TS of the grafted films were recorded and the value was 16.38 MPa. The water uptake and weight loss in both soil and water of the grafted films are lower than the non-grafted films. The prepared films were further characterized with stereo micrograph and XRD. Finally, the produced film can be used as biodegradable packaging materials for shopping and garbage bags that are very popular and environment friendly.

The Preparation and Characterization of a Novolac Cured Epoxy-Clay Nanocomposites

2006 ◽  
Vol 939 ◽  
Author(s):  
Tsung-Yen Tsai ◽  
Shau-Tai Lu ◽  
Chih-Hung Li ◽  
Chin-Jei Huang ◽  
Li-Chun Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Benzalkonium Chloride ◽  
Barrier Properties ◽  
Layered Silicates ◽  
Clay Nanocomposites ◽  
Crosslinking Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTIntercalated or exfoliated nanocomposites were composed by the novolac cured epoxy and one of three different kinds of layered silicates, such as montmorillonite (PK-802), saponite (Semecton-SA) and nontronite (PK-805). The bi-functional modifiers (PI/BEN or MI/BEN) with different ratio, which contained one of the promoters (2-phenylimidazole, PI and 2-methylimidazole, MI) of epoxy and benzalkonium chloride (BEN), were intercalated into the gallery regions of pure clays at the same time and followed by a crosslinking reaction. The properties of novolac cured epoxy/clay nanocomposites were characterized by wild-angle X-ray diffraction (WAXRD), thermal analysis (TGA/DSC), coefficiency of thermal expansion (TMA), mechanical properties (DMA), and transmission electron microscopy (TEM). According to the measurement, these novolac cured epoxy-clay nanocomposites have shown the significant improvement in the thermal, mechanical and barrier properties.

The role of the matrix-filler affinity on morphology and properties of polyethylene/clay and polyethylene/ compatibilizer/clay nanocomposites drawn fibers

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Nadka Tzankova Dintcheva ◽  
Rosamaria Marino ◽  
Francesco Paolo La Mantia
Keyword(s):  
Draw Ratio ◽  
Mechanical Performance ◽  
Extensional Flow ◽  
Cold Drawing ◽  
Clay Nanocomposites ◽  
Structural Variations ◽  
Calorimetric Analysis ◽  
Elongation At Break ◽  
The Matrix

AbstractIn this work the structural variations and mechanical performance of polyethylene/clay nanocomposite drawn fibres, also in the presence of compatibilizer, such as a commercial maleic anhydride grafted polyethylene, PEgMA, was studied. In the isotropic state both systems show intercalated morphology.After spinning and cold drawing, by adding the nanoparticles, the tensile strength as a function of the draw ratio increases and this rise is more pronounced for the filled compatibilized system. The reduction of the elongation at break, on the contrary, is about the same for all the examined samples. The orientation of the macromolecules, evaluated by measurements of the birefringence and calorimetric analysis, is similar for all the samples, but the filled, drawn fibres show a higher level of intercalation and, in particular, some exfoliation, more and more pronounced with the draw ratio and in presence of compatibilizer, as a consequence of the application of the extensional (at low and high temperature) flow. For the three components system with greater affinity between the polymer matrix and clay, the extensional flow is more efficient. The initial intercalated morphology changes to some more intercalation and finally, at the highest anisotropic condition in the presence of the PEgMA, evolves to delaminated clay structure.

Synthesis and Characterization of Biodegradable Aliphatic-Aromatic Copolyesters Nanocomposites Containing POSS

2011 ◽  
Vol 236-238 ◽  
pp. 2028-2031
Author(s):  
Bing Tao Wang ◽  
Yan Zhang ◽  
Zheng Ping Fang
Keyword(s):  
Tensile Strength ◽  
Terephthalic Acid ◽  
Interfacial Adhesion ◽  
Synthesis And Characterization ◽  
Mechanical And Thermal Properties ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Elongation At Break ◽  
The Matrix

Biodegradable aliphatic-aromatic copolyesters/POSS nanocomposites were synthesized via in situ melt copolycondensation of terephthalic acid (TPA), poly(L-lactic acid) oligomer (OLLA), 1,4-butanediol (BDO) and polyhedral oligomeric silsesquioxanes (POSS) reagents (POSS-NH2 and POSS-PEG). The morphologies and dispersions of two POSS reagents in the nanocomposites and their effects on the mechanical and thermal properties were investigated. TEM and XRD characterizations confirmed that POSS-NH2 formed crystalline microaggregates and took poor dispersions in the nanocomposite, while POSS-PEG had better dispersion in the matrix. Due to the good dispersion and interfacial adhesion of POSS-PEG with the copolyester PBTL matrix, the tensile strength and the Young’s modulus greatly increased for PBTL/POSS-PEG nanocomposite. Moreover, compared with POSS-NH2 the existence of POSS-PEG imparted PBTL good flexibility and increased the mobility of the chains, so the glass-transition temperature and the heat of melting as well as the elongation at break were obviously influenced for PBTL/POSS-PEG nanocomposite.

scholarly journals Preparation and Characterization of Porous Scaffolds Based on Poly(3-hydroxybutyrate) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 935
Author(s):  
Asiyah Esmail ◽  
João R. Pereira ◽  
Chantal Sevrin ◽  
Christian Grandfils ◽  
Ugur Deneb Menda ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Porous Scaffolds ◽  
High Porosity ◽  
Solvent Casting ◽  
Elongation At Break ◽  
Particulate Leaching ◽  
Copolymer Poly ◽  
Water Swelling ◽  
Emulsion Templating

Poly(hydroxyalkanoates) (PHAs) with different material properties, namely, the homopolymer poly(3-hydroxybutyrate), P(3HB), and the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate, P(3HB-co-3HV), with a 3HV of 25 wt.%, were used for the preparation of porous biopolymeric scaffolds. Solvent casting with particulate leaching (SCPL) and emulsion templating were evaluated to process these biopolymers in porous scaffolds. SCPL scaffolds were highly hydrophilic (>170% swelling in water) but fragile, probably due to the increase of the polymer’s polydispersity index and its high porosity (>50%). In contrast, the emulsion templating technique resulted in scaffolds with a good compromise between porosity (27–49% porosity) and hydrophilicity (>30% water swelling) and without impairing their mechanical properties (3.18–3.35 MPa tensile strength and 0.07–0.11 MPa Young’s Modulus). These specifications are in the same range compared to other polymer-based scaffolds developed for tissue engineering. P(3HB-co-3HV) displayed the best overall properties, namely, lower crystallinity (11.3%) and higher flexibility (14.8% elongation at break. Our findings highlight the potency of our natural biopolyesters for the future development of novel porous scaffolds in tissue engineering, thanks also to their safety and biodegradability.

The Use of Montmorillonite (MMT) in Food Nanocomposites: Methods of Incorporation, Characterization of MMT/Polymer Nanocomposites and Main Consequences in the Properties

2020 ◽  
Vol 11 (1) ◽  
pp. 13-26
Author(s):  
Fernanda Vilarinho ◽  
Malia Fátima Vaz ◽  
Ana Sanches Silva
Keyword(s):  
Food Packaging ◽  
State Of The Art ◽  
Barrier Properties ◽  
Considerable Improvement ◽  
Clay Nanocomposites ◽  
Uniform Dispersion ◽  
Food Applications ◽  
Dispersion Of Nanoparticles ◽  
New Strategies

Background: The clay Montmorillonite (MMT) is among the nanofillers more frequently used in food packaging. The uniform dispersion of nanoparticles in polymers confers considerable improvement of mechanical, thermal, optical, and/or barrier properties in polymer/clay nanocomposites. Objective: The aim is to ascertain the state of the art of the use of MMT for packaging purposes, with special emphasis on food applications. Methods: A literature review was carried out through recent papers and patents that focused on the incorporation of MMT in polymers. Results: This review emphasizes the interaction of MMT with polymers and their levels of incorporation in the nanocomposites. This work also highlights the analytical methodologies used for the characterization of the polymer/clay nanocomposites and the main consequences of the fillers in the properties of nanocomposites. Challenges remain about increasing the compatibility between clays and biopolymers to promote their utilization in food packaging. New strategies for immobilization of oxides, enzymes, essential oils, and other bioactive compounds are needed. Conclusion: MMT-based composite materials are promising to be used in intelligent and active packaging.

Effect of Organoclay Dispersion on the Barrier Performance and Mechanical Strength of EVA Clay Nanocomposites

2013 ◽  
Vol 747 ◽  
pp. 15-18
Author(s):  
Wilson Runcy ◽  
Kumar S. Anil ◽  
Thomas Sabu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Membranes ◽  
Barrier Properties ◽  
Superior Performance ◽  
Clay Nanocomposites ◽  
Elongation At Break ◽  
Barrier Performance ◽  
Poly Ethylene ◽  
Cloisite 15A

Poly (ethylene-co-vinyl acetate) (EVA)/clay nanocomposites with different clay loadings were prepared. The transport of gases (oxygen and nitrogen) through the composite membranes was investigated. These studies revealed that the incorporation of nanoclays in the polymer increased the efficiency of the membranes toward barrier properties. It was also found that the barrier properties of the membranes decreased with clay loadings. This is mainly due to the aggregation of clay at higher loadings. The mechanical properties of the nanocomposites were analysed. Samples with 5 wt % Cloisite 15A clay showed superior performance in tensile strength and elongation at break.

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