Barrier Properties Of Composite Films Research Articles

Utilization of Pickering emulsion stabilized by chitin nanofibers for improving water and oxygen resistance of gelatin films

The hydrophilicity of gelatin films obviously limits their application. In this work, novel protonated chitin nanofiber was prepared with green methods, surficial deacetylation combined with acidic and mechanical treatment. Composite films with excellent water and oxygen barrier properties were successfully prepared by blending O/W Pickering emulsions stabilized by chitin nanofibers with gelatin substrates. The films were characterized by Fourier-transform infrared, X-ray diffraction, mechanical properties, water and oxygen permeability, moisture content, water solubility, water contact angle and optical properties. The results demonstrated that the amino groups of chitin nanofibers bound to the carboxyl groups of gelatin via electrostatic interactions, which contributing to the excellent mechanical and barrier properties of composite films. The elongation at break of composite film (the concentration of chitin nanofiber was 0.2 wt%) was 2.66 times of gelatin film. And the water vapor and oxygen permeability of composite films lowered to 65.9 % and 52.9 %, respectively. The introduction of O/W Pickering emulsion significantly enhanced the hydrophobicity of gelatin-based film and the chitin nanofibers played a positive role in stabilizing the gelatin chains to a certain extent. This study expands the application fields of gelatin-based films and provides valuable technical route for the preparation of barrier films.

Mechanical and barrier properties of chitosan-based composite film as food packaging: A review

Chitosan can serve as a natural alternative to petroleum-based components in food packaging; however, the mechanical and barrier properties of pure chitosan film possess certain limitations. This paper presents a comprehensive review on the mechanical and barrier properties of composite films formed by combining chitosan-based films with plasticizers, polysaccharides, proteins, and lipids. These composite films often exhibit superior mechanical strength and enhanced barrier performance compared to pure chitosan film, thereby expanding the potential applications of chitosan in food packaging. Chitosan represents an ideal raw material for developing innovative biofilms that can cater to diverse packaging requirements for various food products while offering promising prospects for broad application.

Eggshell powder as a bio-filler for starch and gelatin: Ternary biodegradable composite films manufactured by extrusion compression molding

Recovery of food waste eggshell powder (ESP) as a bio-filler for biopolymer matrix to develop sustainable composites is an attractive recycling strategy nowadays. Herein, biodegradable composite films based on potato starch/gelatin (PS/G) containing different concentrations (0%–50%, w/w, of the total mass of PS/G) of ESP were manufactured using thermal extrusion followed by compression molding. Interaction and compatibility of film components were evaluated by using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Color, opacity, mechanical properties, water vapor and oxygen permeability, and biodegradability of the composite films were also systematically characterized. The existence of hydrogen bonding interactions between the amino groups of organic compounds on ESP surface and the hydroxyl groups of starch and gelatin was confirmed by FTIR, and the ESP particles were uniformly dispersed in the film matrix with good adhesion as observed by SEM. More importantly, the incorporation of ESP at appropriate amount greatly improved water resistance, tensile properties, water vapor and oxygen barrier properties of composite films compared to the control PS/G films. Optimal ESP content in the composite films was found to be ∼30 % w/w in terms of their mechanical and barrier properties, showing a tensile strength of 4.54 MPa, elongation at break of 27.23%, water vapor permeability of 4.16 × 10−10 g m·m−2·s−1·Pa−1 and oxygen permeability of 8.15 × 10−15kg m·m−2·s−1·Pa−1, respectively. Moreover, all the films were able to completely degrade within one month. Thermo-processed PS/G/ESP composite films with desirable physicochemical properties and favorable biodegradability hold great application potential in biodegradable packaging systems.

Starch-based active packaging film and its application

Montmorillonite (MMT) was used to improve the performance of starch and nano-ZnO was added to act as antibacterial agent for developing a starch-based active packaging material via solution mixing and casting methods. The effect of MMT and ZnO on the performance of starch films was investigated, and then the composite films were used for cherry preservation. The results indicated that the addition of MMT could improve the mechanical and water-vapor barrier properties of starch films, but it had only a slight impact on optical properties. However, the addition of nano-ZnO could reduce the optical, mechanical, and water vapor barrier properties of composite films. In preservation applications, compared to the other films, the composite films containing nano-ZnO could be beneficial to maintain quality and nutritional value of cherries by slowing down the growth of bacteria and thereby delaying weight loss, decreasing hardness, and decreasing pH and soluble solid content, resulting in a better preservation effect. Therefore, a starch-based active packaging film with good properties and preservation effect was developed with nano-ZnO and MMT, which could be applied in the field of preservation.

Thermoplastic collagen fiber films improved by bacterial cellulose with high barrier properties

Irradiated bacterial cellulose (mBC) was used to enhance the properties of collagen fiber (CF)-based food packaging films to gradually replace plastic packaging materials. The structural differences between bacterial cellulose (BC) and irradiated bacterial cellulose (mBC) were analyzed, and the heat sealing properties, mechanical properties and barrier properties of CF-mBC composite films were investigated and analyzed. FTIR and XPS results showed that CF and mBC mainly have hydrogen bonding and amide bond formation. The addition of mBC improved the thermal stability of the CF film and increased the heat seal performance, optical properties and mechanical properties from 1 N/15 mm to 8.53 N/15 mm, 82.45 % to 85.02 % and 44.54 MPa to 58.56 MPa, respectively. In addition, the good barrier property of this composite film makes it achieve grade 12 oil-proof under − 9 ℃ to 100 ℃ oil temperature. Therefore, mBC reinforced CF film has a broad application prospect in the food packaging field.

Material and Environmental Properties of Natural Polymers and Their Composites for Packaging Applications-A Review.

The current trend of using plastic material in the manufacturing of packaging products raises serious environmental concerns due to waste disposal on land and in oceans and other environmental pollution. Natural polymers such as cellulose, starch, chitosan, and protein extracted from renewable resources are extensively explored as alternatives to plastics due to their biodegradability, biocompatibility, nontoxic properties, and abundant availability. The tensile and water vapor barrier properties and the environmental impacts of natural polymers played key roles in determining the eligibility of these materials for packaging applications. The brittle behavior and hydrophilic nature of natural polymers reduced the tensile and water vapor barrier properties. However, the addition of plasticizer, crosslinker, and reinforcement agents substantially improved the mechanical and water vapor resistance properties. The dispersion abilities and strong interfacial adhesion of nanocellulose with natural polymers improved the tensile strength and water vapor barrier properties of natural polymer-based packaging films. The maximum tensile stress of these composite films was about 38 to 200% more than that of films without reinforcement. The water vapor barrier properties of composite films also reduced up to 60% with nanocellulose reinforcement. The strong hydrogen bonding between natural polymer and nanocellulose reduced the polymer chain movement and decreased the percent elongation at break up to 100%. This review aims to present an overview of the mechanical and water vapor barrier properties of natural polymers and their composites along with the life cycle environmental impacts to elucidate their potential for packaging applications.

Effect of polymer blending on mechanical and barrier properties of starch-polyvinyl alcohol based biodegradable composite films

The study was aimed to improve the properties of starch-based biodegradable films by the way of polymer blending. The composite films were prepared by incorporating various proportions of PVA (10, 30, 50, 70, and 90% of starch wt.) to the starch using the solvent casting method. All films were analyzed for their mechanical behavior, barrier properties, water solubility, water contact angle, and biodegradability. Incorporation of PVA to starch polymer significantly (p < 0.05) improved the mechanical and barrier properties of composite films. The highest improvement in mechanical behavior was observed for the SP90 composite film, having a higher content of PVA. SP90 film showed 1.93 fold increase in TS, 3.74 fold increase in E and 1.72 fold increase in BS over the pure starch film. On the other hand, maximum PVA incorporation resulted in 52% and 57% decrease in WVP and OP of composite films respectively, depicting a good barrier against water vapour and oxygen gas. Fourier-transform infrared spectroscopy and scanning electron microscopy of films confirmed the excellent compatibility between starch and PVA polymer. Interestingly, the composite films degraded rapidly in moistened soil within 3 weeks of burial. Biodegradability study showed a promising potential of starch-PVA composite films for the development of eco-friendly food packaging material.

Fabrication of anti-bacterial, hydrophobic and UV resistant galactomannan-zinc oxide nanocomposite films

The use of organic and inorganic materials to prepare membrane materials with functional performance has attracted much attention in recent years. In this paper, galactomannan (GM) is used as raw material and nano zinc oxide (nano-ZnO) is used as functional modifier to prepare GM based food packaging films. The properties influence for films of different nano-ZnO content were studied. The obtained nano-ZnO/GM composite films showed superior hydrophobicity and almost absorbing all UVA and UVB. The tensile strength of composite film was superior to plastic HDPE film, and the oxygen barrier properties of composite films were better than PVC plastic film. The composite films against E. coli and B. subtilis showed great antibacterial properties. The antibacterial effect was demonstrated by Shine-Muscat grapes after storage for 5 days. The final prepared GM based functional food packaging film provides a foundation for the potentials for futural plastic packaging alternatives.

Lipophilic modification of T-ZnOw and optical properties of T-ZnOw/PVB composite films

In order to protect the articles in buildings from ultraviolet radiation and save air-conditioning energy, polyvinyl butyral laminated glass are employed and produced in large quantities. Several inorganic particles with blocking effect have been doped into PVB, such as TiO2, ZnO, and ATO. T-ZnOw is a widely used functional structural material with excellent absorption properties. Herein, T-ZnOw was lipophilic modified with silane coupling agent KH-570, and T-ZnOw/PVB composite films were prepared via subsequent solution blending. As per the FTIR spectrum, a characteristic peak of Si–O–Zn at 1165 cm−1 was observed, indicating that T-ZnOw was successfully modified by KH-570. T-ZnOw before and after modification was separately mixed with the St/H2O mixed solution. The modified T-ZnOw could be dispersed in styrene instead of water, displaying a certain lipophilicity. On the other hand, from a microscopic perspective, the SEM images suggest that filling the filler in the form of a suspension can disperse the modified T-ZnOw in PVB in an independent four-needle form, which contributes toward improvement of the agglomeration of T-ZnOw in the PVB matrix. The UV–Vis–NIR spectrum shows that the addition of T-ZnOw reduced the UV transmittance of T-ZnOw/PVB composite films from 50.84 to 25.77%, resulting in a decrease in near-infrared transmittance from 82.14 to 43.22%. The ultraviolet and near-infrared light barrier properties of composite films were more than twice that of the ordinary PVB films. Moreover, the modified T-ZnOw endowed composite films with stronger ultraviolet light and near-infrared light-blocking properties, or better visible light transmittance. And the falling ball impact test proved that there was no clear relationship between the thickness of the film and the adhesion. This work proposes a new solution and preparation method for the production of energy-saving glass. Therefore, it is expected that using composite films instead of traditional PVB films to make laminated glass can greatly contribute toward energy conservation and environmental protection.

The Influence of Kaolin Clay on the Mechanical Properties and Structure of Thermoplastic Starch Films

The aim of study was to investigate the influence of kaolin on the physical properties and utility of film produced from native starch. The work involved measurements of strength, structure, and thermal properties. The films were prepared by the casting method. Composite films with 0%, 5%, 10%, and 15% kaolin additives were examined. Measurements of mechanical properties were carried out using the uniaxial tensile test, the nanoindentation test, and nanoscratching. Surface properties were examined by atomic force microscopy and contact angle measurements. Structure was determined by the X-ray diffraction method, and thermal properties were determined by differential scanning calorimetry. A significant influence of kaolin on the strength parameters and thermal and barrier properties of composite films was found. An increase in kaolin content reduced the tensile strength, Young’s modulus, and Poisson’s ratio. Structural analysis showed a partial intercalation and the layered arrangement of kaolin particles. Kaolin additives increased the barrier properties of water vapor in composite films of about 9%. Biopolymer modification by nanoclay reduced the thermal stability of composite films by 7% and could accelerate the biodegradation process. Increasing the concentration of kaolin in the biopolymer matrix led to heightened surface roughness (approximately 64%) and wettability of the surfaces of the film composites of 58%.

Mechanical and barrier properties of chitosan combined with other components as food packaging film

Chitosan is an alternative to synthetic polymers for food packaging. The mechanical and barrier properties of pure chitosan films are promising. Chitosan properties can be modified by combining chitosan with other components such as plasticizers, other polysaccharides, proteins and lipids. Here we review mechanical and barrier properties of composite films based on chitosan. The major points are: (1) compared with synthetic plastic films, an important limitation of chitosan-based films is their mechanical properties, especially their capacity to elongation; (2) chitosan is a polymer that allows an easy combination with other polysaccharides, plasticizers, proteins and lipids; (3) this allows to develop mixed components and modify the film properties according to the nature of the food to be packaged.

Effect of High Pressure Treatment on Poly(lactic acid)/Nano⁻TiO₂ Composite Films.

The microstructure, thermal properties, mechanical properties and oxygen and water vapor barrier properties of a poly(lactic acid) (PLA)/nano-TiO2 composite film before and after high pressure treatment were studied. Structural analysis showed that the functional group structure of the high pressure treated composite film did not change. It was found that the high pressure treatment did not form new chemical bonds between the nanoparticles and the PLA. The micro-section of the composite film after high pressure treatment became very rough, and the structure was depressed. Through the analysis of thermal and mechanical properties, high pressure treatment can not only increase the strength and stiffness of the composite film, but also increase the crystallinity of the composite film. Through the analysis of barrier properties, it is found that the barrier properties of composite films after high pressure treatment were been improved by the applied high pressure treatment.

Development of ultrasound treated polyvinyl alcohol/tea polyphenol composite films and their physicochemical properties

In this study, polyvinyl alcohol (PVA) was used as a film-forming substrate, added to extracted tea polyphenols (TPs) in various ratios and processed with ultrasonication to form films using the tape-casting method. The effects of ultrasonic processing duration on the properties of PVA/TP antibacterial active materials were explored via material property testing. The results showed that, overall, ultrasonic processing degraded the tensile strength and elongation at break of the composite films. When PVA/TP composite films with a PVA-to-TP mass ratio of 8:2 were processed with ultrasonication for 30 min, the swelling capacity was (740.19 ± 64.67)% and solubility was (5.26 ± 1.31)%. Ultrasonication also improved the degradability and barrier properties of composite films. Moreover, 8/2 composite films with the PVA/TP ratio of 8:2 exhibited excellent bacteriostatic properties; after ultrasonication processing, the films had a bacteriostatic rate of (95.5 ± 4.2)% and (91.8 ± 3.7)% against Staphylococcus aureus and Escherichia coli, respectively, making them suitable for use as antibacterial active materials in food packaging.

Effects of Corn Starch and Kappaphycus alvarezii Seaweed Blend Concentration on the Optical, Mechanical, and Water Vapor Barrier Properties of Composite Films

Composite films with different Kappaphycus alvarezii seaweed and corn starch concentrations were developed, and the effect of these concentrations on the films’ optical, mechanical, and water vapor barrier properties were investigated. The chemical interactions between the two components in the film were verified by chemical composition and Fourier transform infrared (FTIR) spectroscopy investigations. The results showed that the mechanical properties and opacity of the composite films were enhanced with the addition of seaweed. Among the compositions, a composite film with 3% seaweed and 1% starch exhibited the highest tensile strength and elongation at break. The water vapor permeability (WVP) of the composite films linearly increased with the increments of starch and seaweed concentrations. The FTIR analysis also revealed intermolecular interactions between the two components, consistent with the good miscibility of seaweed and starch in the blend. Therefore, different concentrations of the blend of seaweed and starch could be used to tailor a film with certain desired functional properties.

Functional properties of dually modified sago starch/κ-carrageenan films: An alternative to gelatin in pharmaceutical capsules

The aim of this study was development a composite film based on sago starch and κ-carrageenan to find a gelatin alternative in the pharmaceutical capsules processing. Hydrolyzed-Hydroxypropylated (dually modified) sago starch was mixed with κ-carrageenan (0.25, 0.5, 0.75, and 1%). The drying kinetics, thermomechanical, physicochemical, and barrier properties of composite films were estimated and compared with bovine gelatin. Results show that drying kinetics and mechanical properties of the composite films were comparable to those of gelatin. The water vapor permeability and moisture content of the composite films were lower than those of gelatin. The solubility of the composite films was higher than that of gelatin, and the composite films were more stable at higher relative humidity than were the gelatin films. These results show that dually modified sago starch in combination with κ-carrageenan has properties similar to those of gelatin, thus proposed system can be used in pharmaceutical capsules processes.

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

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 &lt; 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.

Clay‐filled starch films. Part I: Effect of clay kind and glycerol concentration on functional properties of composites

The aim of this work was to improve the mechanical and water barrier properties of composite films prepared from starch and clays, plasticized with glycerol at different concentrations. The effects of hydrophilic Closite Na+ and Nanomer PGV were compared with that exerted by organically modified more hydrophobic Nanofil 2 and NanoBent ZR‐1. The antimicrobial activity of composites containing hydrophobic clays was also investigated. The hydrophilic Nanomer PGV at concentrations of 5–10% increased the tensile strength (TS) of unplasticized composites, but starch‐Closite Na+ composites were too brittle to measure their mechanical properties. The hydrophobic clays did not improve the mechanical properties of the unplasticized composites. In the presence of glycerol at concentrations of 20–30%, TS of composites containing hydrophilic clays and even hydrophobic NanoBent ZR‐1 increased in comparison to plasticized films without clay. None of the clays improved the water barrier properties of the unplasticized composites, while in the plasticized composites all the clays decreased the water vapor permeability to an extent dependent on the kind and concentration of clay and glycerol concentration. Starch‐NanoBentZR‐1 composite showed very high activity against gram‐positive Staphylococcus aureus and Listeria innocua. Starch‐Nanofil 2 composites were characterized by smaller activity. Neither composite showed any antimicrobial activity, or their activity against gram‐negative bacteria was low.

Effect of Sodium Alginate on the Properties of Composite Protein Films

Effects of sodium alginate on properties of WPI-NaCas composite films optimized by previous uniform design experiments were investigated. Films were prepared with different concentrations (1%, 2%, 3%) and ratios (1:0, 5:1, 3:1, 1:1, 1:3, 1:5, 0:1, ratio of composite protein solution to sodium alginate solution) of sodium alginate additions. Results suggested increases in water solubility of films and middle diameter, volume-length mean diameter and area-length mean diameter of film-forming solutions. Addition of sodium alginate decreased the gas and water vapor barrier properties of composite films, however, their mechanical properties could be improved by proper usage. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope analysis indicated that protein and sodium alginate presented well interaction and compatibility.

Physical and Barrier Properties of Apple Pectin/Cassava Starch Composite Films Incorporating L aurus nobilis L. Oil and Oleic Acid

Edible composite films were prepared from apple pectin/cassava starch, 1.5% (w/v), containing different concentrations of Laurus nobilis L. oil and oleic acid (0.5, 1.0 and 1.5% v/w). The effects of L. nobilis L. oil on the physical properties of the resulted composite films were investigated. Samples with 1.5% (v/w) L. nobilis L. oil showed increased thickness (43.55–51.73 μm) and improved opacity; their barrier properties to UV radiation in the range of 200–280 nm significantly (P < 0.05) increased compared with that of the control film. The water vapor permeability of the films was reduced to 1.56 (g·mm/m2·day ·Pa) by adding more oil. The effect of L. nobilis L. oil on the oxygen permeability was lower (0.31 cc/m2/day). The measurement of color values showed that by increasing the oil content in polymer matrix, the L* values (lightness) and whiteness index decreased (P < 0.05), whereas the b* values (yellowness), a* values (greenness), yellowness index and total color difference (ΔE) of the films increased (P < 0.05). The surface microstructure of the matrix films was analyzed using atomic force microscopy, and the surface structures of the films were determined using scanning electron microscopy. The mechanical properties were also affected by the addition of L. nobilis L. oil; the tensile strength was diminished, and elongation at breaking (E) increased considerably. Incorporating L. nobilis L. oil provides a novel way to enhance the physical and barrier properties of composite films. Practical Applications Research studies on edible films have received considerable attention in the recent years because of their capability to improve global food quality with all indications that interest will continue. Edible composite films were prepared from apple pectin/cassava starch containing different concentrations of Laurus nobilis L. oil and oleic acid. Edible film materials have been developed mainly because of their advantages, such as they are being used as edible packaging materials over synthetic films. The functional properties of edible films are greatly influenced by parameters such as formulation from polysaccharide, which have been suggested as a means of food protection, and preservation could contribute to the reduction of environmental pollution, film forming technology, solvent characteristics and additives.

Influence of maleic anhydride-grafted polyethylene compatibiliser on the tensile, oxygen barrier and thermal properties of rice husk and nanoclay-filled low-density polyethylene composite films

Rice husk and nanoclay (montmorillonite)-filled low-density polyethylene composite films were prepared by extrusion blown film. Maleic anhydride-modified polyethylene was used as compatibiliser in various concentrations ranging from 0 to 8 parts per hundred. X-ray difractograms showed an increase in interlayer spacing of montmorillonite from the use of compatibiliser when compared to the uncompatibilised composites; an increase of 20, 33, 36 and 38% for 2, 4, 6 and 8 parts per hundred, respectively, of maleic anhydride-modified polyethylene. With the incorporation of maleic anhydride-modified polyethylene, a better dispersion of the fillers was also achieved, as confirmed by scanning electron microscopy. The compatibilised composite films showed improved tensile and barrier properties. The addition of 4 parts per hundred of the compatibiliser resulted in an improvement by 22% in tensile strength. Furthermore, oxygen barrier property of the composite films improved more than twofold by adding 4 parts per hundred of maleic anhydride-modified polyethylene. This improvement in tensile and barrier properties is due to an increase in the interfacial adhesion between the fibre and matrix and better dispersion of impermeable nanoparticles.