scholarly journals Preparation and Characterization of κ-Carrageenan Modified with Maleic Anhydride and Its Application in Films

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 486
Author(s):  
Yuan Zhou ◽  
Fu-Quan Chen ◽  
Si Chen ◽  
Qiong Xiao ◽  
Hui-Fen Weng ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Uv Light ◽  
Barrier Properties ◽  
Water Contact ◽  
Elongation At Break ◽  
Gelling Temperature ◽  
Film Forming ◽  
The Fourier Transform ◽  
Property Changes

In this work, the physicochemical properties of maleic anhydride (MAH)-modified κ-carrageenan (κCar) (MC) were characterized and compared with those of native κ-carrageenan (NC). The Fourier transform infrared spectrum of MC exhibited that κCar was successfully modified. Thermogravimetric analysis indicated that the thermal stability of MC was decreased. When the degree of substitution was 0.032, MC exhibited a low gel strength (759 g/cm2), gelling temperature (33.3 °C), and dehydration rate (60.3%). Given the excellent film-forming ability of κCar, MC films were then prepared and were found to have better mechanical and barrier properties (UV and water) than NC films. With regard to optical properties, MC films could completely absorb UV light in the range of 200–236 nm. The water contact angle of MC films was higher than that of NC films. Moreover, the elongation at break increased from 26.9% to 163%. These physicochemical property changes imply that MC can be employed in polysaccharide-based films.

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.

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.

Preparation and Characterization of Heparin-Immobilized Poly(Ether Urethanes)

2011 ◽  
Vol 393-395 ◽  
pp. 236-239
Author(s):  
Li Ming Lian ◽  
Bing Leng ◽  
Xiao Hua Ma
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Aqueous Solutions ◽  
Fourier Transform Infrared Spectroscopy ◽  
Toluidine Blue ◽  
Water Contact ◽  
The Fourier Transform ◽  
Hydrolysis Of

Heparin (Hep)-immobilized poly(ether urethanes) (PU) was prepared by a unique preparation procedure. Firstly, the poly(ether urethanes)(PU) containing diester groups in the side chains were synthesized. Then, PU was dispersed in aqueous solutions and immobilized with heparin after the hydrolysis of diester groups and carboxylation. The Fourier transform infrared spectroscopy (FTIR) and water contact angle (WCA) were used to characterize the heparin-bonded PU. The amount of heparin grafted on the PU was determined to be 0.57wt.% by the toluidine blue method. The heparin-immobilized PU could release just 12% of the immobilized heparin in the early 10 hours of the 70 hours immobilized heparin stability test.

scholarly journals Synthesis and Characterization of Biodegradable Polyester/Polyether WPU As The Environmental Protection Coating

2021 ◽  
Author(s):  
Guangfeng Wu ◽  
Xin Song ◽  
ZhiHui Yang ◽  
Ying Chun Li ◽  
HuiXuan Zhang
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Degradation Rate ◽  
Soft Segment ◽  
Buffer Solution ◽  
Water Contact ◽  
Elongation At Break ◽  
Protection Coating

Abstract Polyester diol PCL and PBA, polyether diol PTMG and polycarbonate diol PCDL were used as components of WPU soft segment, respectively. Polyether PTMG-WPU has the worst hydrolytic property and the highest thermal stability. The maximum degradation rate temperature Tmax is 407.8°C, the water contact angle reaches 89.5°. Traditional polyester PCL-WPU shows the strongest hydrolysis performance, the smallest water contact angle, only 71.7°, the water absorption rate of 72 hours at room temperature is as high as 26.7%. However, the thermal stability of PCL-WPU is lower, the soft segment Tg is -52.3°C, and Tmax is only 333.7°C, but the mechanical propertie of which is the best, the tensile strength is 58.3 MPa, and the elongation at break reaches 857.9%. The most important thing is that the structure of polyester PCL-WPU is more easily destroyed by lipase and water molecules. The acidic products produced after hydrolysis will further promote the degradation of polyester. Therefore, compared with other WPUs, PCL -WPU has the best biodegradability and the most obvious degradation effect under the same conditions. The degradation rate of PTMG-WPU after 30 days of degradation in 0.6% lipase PBS buffer solution and soil was only 4.2% and 2.3%, while the highest degradation rate of traditional polyester PCL-WPU reached 41.7% and 32.0%, respectively. In addition, polycarbonate PCDL-WPU has the highest hardness, reaching 95.5 HD. But its other performances are lower than PCl-WPU.

scholarly journals Physical and Morphological Characterization of Chitosan/Montmorillonite Films Incorporated with Ginger Essential Oil

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 700 ◽  
Author(s):  
Victor Gomes Lauriano Souza ◽  
João Ricardo Afonso Pires ◽  
Carolina Rodrigues ◽  
Patricia Freitas Rodrigues ◽  
Andréia Lopes ◽  
...  
Keyword(s):  
Essential Oil ◽  
Uv Light ◽  
Barrier Properties ◽  
Morphological Characterization ◽  
Morphological Properties ◽  
Unsaturated Fat ◽  
Light Barrier ◽  
Bionanocomposite Films ◽  
Oxidative Processes

Novel bionanocomposite films of chitosan/montmorillonite (CS/MMT) activated with ginger essential oil (GEO) were produced and characterized in terms of their physical and morphological properties. The homogenization process led to a good interaction between the chitosan and the nanoparticles, however the exfoliation was diminished when GEO was incorporated. Film glass transition temperature did not statistically change with the incorporation of either MMT or GEO, however the value was slightly reduced, representing a relaxation in the polymer chain which corroborated with the mechanical and barrier properties results. Pristine chitosan films showed excellent barrier properties to oxygen with a permeability of 0.184 × 10−16 mol/m·s·Pa being reduced to half (0.098 × 10−16 mol/m·s·Pa) when MMT was incorporated. Although the incorporation of GEO increased the permeability values to 0.325 × 10−16 mol/m·s·Pa when 2% of GEO was integrated, this increment was smaller with both MMT and GEO (0.285 × 10−16 mol/m·s·Pa). Bionanocomposites also increased the UV light barrier. Thus, the produced bioplastics demonstrated their ability to retard oxidative processes due to their good barrier properties, corroborating previous results that have shown their potential in the preservation of foods with high unsaturated fat content.

scholarly journals Fabrication and Characterization of MSQ Aerogel Coating on ePTFE Thin Films for Cable Sheaths

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1246 ◽  
Author(s):  
Xingzhong Guo ◽  
Shengchi Bai ◽  
Jiaqi Shan ◽  
Wei Lei ◽  
Ronghua Ding ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Coating Layer ◽  
Sol Gel ◽  
Raw Material ◽  
Elongation At Break ◽  
High Uniformity ◽  
Film Forming ◽  
Temperature Heat Treatment ◽  
Electrical Insulation Properties

With methylsilsesquioxane (MSQ) aerogels synthesized by the sol-gel method as a raw material and Si-Ti sol as a binder, an alcohol-based aerogel slurry consisting of only MSQ aerogel and Si-Ti sol was prepared and coated on expanded polytetrafluoroethylene (ePTFE) to form an MSQ aerogel coating layer, followed by low-temperature heat treatment. The effect of Si-Ti sol content on the microstructure of the MSQ aerogel coating layer was investigated, and the properties of a typical MSQ aerogel-layer-coated ePTFE film were evaluated. The results show that Si-Ti sol has an important role in terms of film-forming capability, surface smoothness, flexibility, and powder dropping of the MSQ aerogel coating layer. With a Si-Ti sol of 10.5 wt.% content as a binder and after heat treatment at 170 °C for 30 min, the coated ePTFE flexible thin film with a layer thickness of 30 μm shows high uniformity, integrity, and electrical insulation properties, with an elongation at break decrease over 130%, a thermal conductivity of 0.1753 W/(m·K) at 25 °C, a dielectric constant of 16.5674, and a dielectric loss of 0.06369, which can be promisingly applied in cable sheaths.

scholarly journals Stability of Film-Forming Dispersions: Affects the Morphology and Optical Properties of Polymeric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1464
Author(s):  
Maria Gabriela De Paola ◽  
Rosy Paletta ◽  
Catia Giovanna Lopresto ◽  
Giuseppe Emanuele Lio ◽  
Antonio De Luca ◽  
...  
Keyword(s):  
Optical Properties ◽  
Phase Separation ◽  
Food Packaging ◽  
Uv Light ◽  
Ultra Violet ◽  
Dispersed Phase ◽  
Significant Information ◽  
Film Forming ◽  
Light Protection

Starch-based films are promising alternatives to synthetic films in food packaging. They were widely studied in terms of mechanical and optical properties. In food packaging, optical properties are of great interest because ultra violet (UV-light) protection is strictly required. Nevertheless, the characterization of film-forming dispersions was poorly addressed, especially regarding its correlation with the film produced. In this work, we characterized film-forming dispersions at different compositions of starch and carboxymethyl cellulose (CMC) by Turbiscan. This instrument is based on multiple light scattering and gives significant information about the miscibility of polymers in the dispersed phase. Indeed, it identifies the phenomena of destabilization and phase separation before their visibility to the unaided eye. This work aimed to study whether the homogeneous/inhomogeneous morphology of films could be forecast by the analysis of profiles obtained in the dispersed phase. The films produced were investigated by optical microscopy and absorbance analysis. As the CMC fraction increased, Turbiscan showed reduced phase separation. This implies better miscibility of mixture components and higher gelification degree. The related film was more homogeneous and presented higher UV absorbance. Consequently, film-forming dispersions and optical properties of films are strictly correlated and Turbiscan-based analysis is very useful to investigate the dispersion stability and predict the film quality.

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 Preparation and Characterization of Chitosan/Agar Blended Films: Part 2. Thermal, Mechanical, and Surface Properties

2012 ◽  
Vol 9 (2) ◽  
pp. 510-516 ◽  
Author(s):  
Esam A. Elhefian ◽  
Mohamed Mahmoud Nasef ◽  
Abdul Hamid Yahaya
Keyword(s):  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Water Contact ◽  
Elongation At Break ◽  
Angle Measurements ◽  
Static Water Contact Angle ◽  
Contact Angle Measurements ◽  
Static Water ◽  
Thermal Stability Of

Chitosan/agar (CS/AG) films were prepared by blending different proportions of chitosan and agar (considering chitosan as the major component) in solution forms. The thermal stability of the blended films was studied using thermal gravimetric analysis (TGA). It was revealed that chitosan and agar form a compatible blend. Studying the mechanical properties of the films showed a decrease in the tensile strength and elongation at break with increasing agar content. Blending of agar with chitosan at all proportions was found to form hydrogel films with enhanced swelling compared to the pure chitosan one. Static water contact angle measurements confirmed the increasing affinity of the blended films towards water suggesting that blending of agar with chitosan improves the wettability of the obtained films.

scholarly journals Development of Chitosan/Peptide Films: Physical, Antibacterial and Antioxidant Properties

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1193
Author(s):  
Chen Li ◽  
Jiliu Pei ◽  
Shengyu Zhu ◽  
Yukang Song ◽  
Xiaohui Xiong ◽  
...  
Keyword(s):  
Food Packaging ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Barrier Properties ◽  
Surface Hydrophobicity ◽  
Elongation At Break ◽  
Chitosan Films ◽  
Dpph Scavenging

Chitosan/peptide films were prepared by incorporating peptides (0.4%, w/v) from soy, corn and caseins into chitosan films. The presence of peptides significantly affected the physical, antibacterial and antioxidative properties of chitosan films. Among these films, those containing corn peptide showed the best water vapor barrier properties, and the tensile strength and elongation at break increased to 24.80 Mpa and 23.94%, respectively. Characterization of surface hydrophobicity and thermal stability suggested the strongest intermolecular interactions between corn peptides and chitosan. Moreover, films containing casein peptides showed the highest antibacterial activity and radical scavenging activity. The DPPH scavenging rate of films containing casein peptides reached 46.11%, and ABTS scavenging rate reached 66.79%. These results indicate the chitosan/peptide films may be promising food packaging materials.

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