Few-layer graphene aqueous suspensions for polyurethane composite coatings

ABSTRACTGraphite nanoplates (GnP) have recently attracted attention as an economically viable alternative for the development of functional and structural nanocomposites. The incorporation of GnP into waterborne polyurethane (WPU) with loadings from 0.1 to 10 wt.% was studied. The mechanical properties of the composite films were assessed by tensile testing showing an increase of the Young’s modulus up to 48%. The electrical conductivity increased by 9 orders of magnitude and the water vapor permeability of the composite films decreased 57% for composites containing 5.0 wt.% of GnP.

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Fabrication of Composite Films Based on Chitosan and Vegetable-Tanned Collagen Fibers Crosslinked with Genipin

Journal of the American Leather Chemists Association ◽

10.34314/jalca.v116i10.4616 ◽

2021 ◽

Vol 116 (10) ◽

Author(s):

Jie Liu ◽

Yanchun Liu ◽

Eleanor M. Brown ◽

Zhengxin Ma ◽

Cheng-Kung Liu

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Water Vapor ◽

Composite Film ◽

Composite Films ◽

Value Added ◽

Water Vapor Permeability ◽

Vapor Permeability ◽

Leather Industry ◽

Compact Structure

The leather industry generates considerable amounts of solid waste and raises many environmental concerns during its disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor permeability and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging.

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Physical Properties of Starch/Powdered Activated Carbon Composite Films

Polymers ◽

10.3390/polym13244406 ◽

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.

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Composite Films of Waterborne Polyurethane and Few-Layer Graphene—Enhancing Barrier, Mechanical, and Electrical Properties

Journal of Composites Science ◽

10.3390/jcs3020035 ◽

2019 ◽

Vol 3 (2) ◽

pp. 35

Author(s):

Eunice Cunha ◽

Maria Paiva

Keyword(s):

Electrical Properties ◽

Aqueous Suspension ◽

Composite Films ◽

Spray Coating ◽

Waterborne Polyurethane ◽

Free Standing ◽

Layer Graphene ◽

Mechanical And Electrical Properties ◽

Thermal And Electrical Properties ◽

Few Layer Graphene

Graphene has excellent mechanical, thermal, and electrical properties. Graphene can serve as potential reinforcement in polymer-based nanocomposites. In order to achieve this goal, graphene has to be distributed homogeneously and dispersed throughout the polymer matrix, establishing a strong interface with the polymer. Solution mixing is an interesting method for the preparation of homogeneous nanocomposites, in particular when using environmentally friendly solvents such as water. The major difficulty met in the production of graphene/polymer composites concerns the preparation and stabilization of graphene in aqueous suspension. In the present work three different graphite-based materials, with different crystallinity and purity grades, were exfoliated in aqueous solution of an amphiphilic pyrene derivative, forming few-layer graphene (FLG). The FLG prepared was dispersed in waterborne polyurethane (WPU) to produce composite films. The composite films were produced by solvent casting and spray coating, forming free-standing films that were characterized in terms of its distribution of FLG through the composite, its permeability to water vapor, its electrical resistivity, and its mechanical properties. The studies demonstrated the influence of different factors on the composite film properties such as the use of graphite vs. FLG, the FLG lateral dimensions, and the FLG composition and composite preparation method.

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Effect of Nanoalumina on the Electrochemical and Mechanical Properties of Waterborne Polyurethane Composite Coatings

Journal of Nanoparticles ◽

10.1155/2013/527432 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 6

Author(s):

Shailesh K. Dhoke ◽

Narayani Rajgopalan ◽

A. S. Khanna

Keyword(s):

Mechanical Properties ◽

Morphological Changes ◽

Steel Substrate ◽

Composite Coatings ◽

Salt Spray ◽

Waterborne Polyurethane ◽

Nanocomposite Coating ◽

Test Method ◽

Pencil Hardness ◽

Polyurethane Composite

A nanocomposite coating was formed by incorporating nanoalumina pigment in a waterborne polyurethane dispersion (WPUD) to different loading levels (0.1% and 1.0% by weight). Electrochemical performance of the nanocomposite coating was evaluated by applying these nanomodified coatings on mild steel substrate and exposing them to salt-spray, humidity, and accelerated UV weathering. The surface morphology of the composite coating was evaluated using various analytical techniques. SEM and AFM were used to investigate the dispersion of nanoalumina pigment and surface morphological changes of the nanomodified coating, before and after exposure to the test environment. Mechanical properties like scratch resistance were studied by using nanoscratch technique (Nanoindenter TI-900, Hysitron Inc, USA) and hardness using pencil hardness test method. The results showed an improvement in the corrosion, UV weathering, and mechanical properties of the coatings at lower concentration (0.1% by wt), indicating the positive effect of addition of nanoalumina pigment to the coating.

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

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0014 ◽

2016 ◽

Vol 36 (2) ◽

pp. 181-188 ◽

Cited By ~ 5

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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Influence of Ammonium Zirconium Carbonate on Properties of Poly(vinyl alcohol)/Xylan Composite Films

Journal of Nanomaterials ◽

10.1155/2015/810464 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Xiao-feng Chen ◽

Jun-li Ren ◽

Ling Meng

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Vinyl Alcohol ◽

Positive Impact ◽

Raw Materials ◽

Composite Films ◽

Water Vapor Permeability ◽

Poly Vinyl Alcohol ◽

Vapor Permeability ◽

Ammonium Zirconium Carbonate

A series of composite films were prepared using poly(vinyl alcohol) (PVA) and xylan as degradable raw materials under the addition of glycerol and ammonium zirconium carbonate (AZC). The influences of AZC on the mechanical properties, water-resisting properties, thermal stability, solubility (S), and water vapor permeability of PVA/xylan composite films were comparatively discussed. The results showed that AZC had a positive impact on improving the water resistance and mechanical properties of composite films especially for elongation at break (EAB). With increasing the AZC amounts from 0% to 15%, EAB increased rapidly from 18.5% to 218.0%, and theSvalues decrease from 11.64% to 8.64%. When the AZC amount reached 15%, the tensile strength still performed well (22.10 MPa). The great compatibility of components in composite films was also observed. Moreover, the addition of AZC had great influences on the thermal stability of composite films and the degradation in soil.

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Preparation and Characterization of Chinese Leek Extract Incorporated Cellulose Composite Films

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.731749 ◽

2021 ◽

Vol 9 ◽

Author(s):

Qiying Zeng ◽

Naiyu Xiao ◽

Xueqin Zhang ◽

Wenhan Luo ◽

Gengshen Xiao ◽

...

Keyword(s):

Mechanical Properties ◽

Composite Films ◽

Volume Ratio ◽

Water Vapor Permeability ◽

Vapor Permeability ◽

Force Microscopy ◽

Atomic Force ◽

Biocomposite Films ◽

Potential Applications ◽

Biocomposite Film

This study aimed to prepare microcrystalline cellulose (MCC) films with good mechanical properties via plasticization using a Chinese leek (CL, Allium tuberosum) extract. The microstructure, crystal structure, mechanical properties, barrier ability, and thermal properties of the films were investigated. The chemical structure analysis of CL extract showed the existence of cellulose, lignin, and low-molecular-weight substances, such as polysaccharides, pectins, and waxes, which could act as plasticizers to enhance the properties of MCC:CL biocomposite films. The results of scanning electron microscopy and atomic force microscopy analyses indicated the good compatibility between MCC and CL extract. When the volume ratio of MCC:CL was 7:3, the MCC:CL biocomposite film exhibited the best comprehensive performance in terms of water vapor permeability (2.11 × 10–10 g/m·s·Pa), elongation at break (13.2 ± 1.8%), and tensile strength (24.7 ± 2.5 MPa). The results of a UV absorption analysis demonstrated that the addition of CL extract improved the UV-shielding performance of the films. Therefore, this work not only proposes a facile method to prepare MCC films with excellent mechanical properties via plasticization using CL extract but also broadens the potential applications of MCC films in the packaging area.

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Application of Solution Blow Spinning for Rapid Fabrication of Gelatin/Nylon 66 Nanofibrous Film

Foods ◽

10.3390/foods10102339 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2339

Author(s):

Zhichao Yang ◽

Chaoyi Shen ◽

Yucheng Zou ◽

Di Wu ◽

Hui Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Water Vapor ◽

Composite Film ◽

Food Packaging ◽

Composite Films ◽

Water Vapor Permeability ◽

Vapor Permeability ◽

Nylon 66 ◽

Rapid Fabrication ◽

Solution Blow Spinning

Gelatin (GA) is a natural protein widely used in food packaging, but its fabricated fibrous film has the defects of a high tendency to swell and inferior mechanical properties. In this work, a novel spinning technique, solution blow spinning (SBS), was used for the rapid fabrication of nanofiber materials; meanwhile, nylon 66 (PA66) was used to improve the mechanical properties and the ability to resist dissolution of gelatin films. Morphology observations show that GA/PA66 composite films had nano-diameter from 172.3 to 322.1 nm. Fourier transform infrared spectroscopy and X-ray indicate that GA and PA66 had strong interaction by hydrogen bonding. Mechanical tests show the elongation at break of the composite film increased substantially from 7.98% to 30.36%, and the tensile strength of the composite film increased from 0.03 MPa up to 1.42 MPa, which indicate that the composite films had the highest mechanical strength. Water vapor permeability analysis shows lower water vapor permeability of 9.93 g mm/m2 h kPa, indicates that GA/PA66 film’s water vapor barrier performance was improved. Solvent resistance analysis indicates that PA66 could effectively improve the ability of GA to resist dissolution. This work indicates that SBS has great promise for rapid preparation of nanofibrous film for food packaging, and PA66 can be applied to the modification of gelatin film.

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

10.21203/rs.3.rs-672111/v1 ◽

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.

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Composite Film Based on Pulping Industry Waste and Chitosan for Food Packaging

Materials ◽

10.3390/ma11112264 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2264 ◽

Cited By ~ 6

Author(s):

Ji-Dong Xu ◽

Ya-Shuai Niu ◽

Pan-Pan Yue ◽

Ya-Jie Hu ◽

Jing Bian ◽

...

Keyword(s):

Mechanical Properties ◽

Oxygen Transfer ◽

Transfer Rate ◽

Food Packaging ◽

Oxygen Transfer Rate ◽

Composite Films ◽

Water Vapor Permeability ◽

Vapor Permeability ◽

Low Oxygen ◽

Content Ratio

Wood auto-hydrolysates (WAH) are obtained in the pulping process by the hydrothermal extraction, which contains lots of hemicelluloses and slight lignin. WAH and chitosan (CS) were introduced into this study to construct WAH-based films by the casting method. The FT-IR results revealed the crosslinking interaction between WAH and CS due to the Millard reaction. The morphology, transmittance, thermal properties and mechanical properties of composite WAH/CS films were investigated. As the results showed, the tensile strength, light transmittances and thermal stability of the WAH-based composite films increased with the increment of WAH/CS content ratio. In addition, the results of oxygen transfer rate (OTR) and water vapor permeability (WVP) suggested that the OTR and WVP values of the films decreased due to the addition of CS. The maximum value of tensile strengths of the composite films achieved 71.2 MPa and the OTR of the films was low as 0.16 cm3·μm·m−2·24 h−1·kPa−1, these properties are better than those of other hemicelluloses composite films. These results suggested that the barrier composite films based on WAH and CS will become attractive in the food packaging application for great mechanical properties, good transmittance and low oxygen transfer rate.

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