Ethylene-tetrafluoroethylene Copolymer Research Articles

Electrostatic spraying of zinc carbonate hydroxide-infused ethylene-tetrafluoroethylene powders: A thermally-induced, VOC-free antibacterial superhydrophobic coating

This study introduces an environmentally friendly method to create a superhydrophobic antibacterial coating using electrostatic powder spraying. The process utilizes ethylene-tetrafluoroethylene copolymer (ETFE) and zinc carbonate hydroxide (ZCH) powders and no organic solvent was used. The resulting coating takes advantage of ETFE's hydrophobic properties and the microstructure generated from ZCH's thermal decomposition, producing a micrometer-scale porous structure with a water contact angle of 165°. It demonstrates strong adhesion to substrates, fulfilling grade 0 standards as per GB/T 9286–2021 / ISO 2409:2020. Following 3 cycles of the falling-sand test, as outlined by ISO/TS 10689:2023, the contact angle impressively remains above 150°, underscoring its extraordinary resistance in contrast to coatings described in literature that typically endure just about 1 cycle. Even after 10 cycles of high-speed water jet impacts following ISO/TS 10689:2023, it maintains a water contact angle of 145°, equivalent to resisting ten years of continuous rainfall based on ISO/TS 10689:2023. The coating's antibacterial effectiveness, stemming from its superhydrophobic characteristics and the antibacterial properties of ZnO produced by ZCH decomposition, achieves inhibition rates of 99.6 % and 99.8 % against E. coli (ATCC 25922) and S. aureus (ATCC 6538) respectively, highlighting its significant potential for practical applications.

Hydrophilicity regulation and microstructure change of Ethylene-tetrafluoroethylene copolymer films grafted acrylic acid by irradiation-induced co-grafting

The surface hydrophobicity of Ethylene-tetrafluoroethylene copolymer(ETFE) films limits its application in functional membranes. However, the surface energy of ETFE films is extremely low and the interface compatibility is poor, which makes it difficult to modify the surface hydrophilicity. In this work, acrylic acid was grafted onto ETFE films by the irradiation-induced co-grafting method. The effects of adsorbed dose on the structure and properties of grafted ETFE films were investigated by the various characterization methods. By irradiation- induced grafting method, the surface of ETFE films were successfully grafted with acrylic acid to modify its hydrophilicity. With the increase of absorbed dose, the contact angle of the ETFE was reduced from 102° to 44°, the microstructure and the natural crystallization area was destroyed, and the radius of gyration decreased. The destruction of the structure leads to a decrease in mechanical properties. When the absorbed dose is 60 kGy, it exhibits good hydrophilicity and mechanical properties. The contact angle, breaking strength and elongation at break are 68°, 13.0 MPa and 72.6 %, respectively. It clarified the effect of adsorbed dose on the structure of ETFE grafted acrylic acid, and helped to expand the application of ETFE in battery separators and other fields.

Effect of Gamma Radiation Dose on the Crystal Structure of the Ethylene–Tetrafluoroethylene Copolymer

Effect of Gamma Radiation Dose on the Crystal Structure of the Ethylene–Tetrafluoroethylene Copolymer

Effect of Ionizing Radiation on Electrical Conductivity of a Tetrafluoroethylene–Ethylene Copolymer Containing Single-Wall Carbon Nanotubes

Effect of Ionizing Radiation on Electrical Conductivity of a Tetrafluoroethylene–Ethylene Copolymer Containing Single-Wall Carbon Nanotubes

Effect of Protective Layer on the Performance of Monocrystalline Silicon Cell for Indoor Light Harvesting.

The development of renewable energy sources has grown increasingly as the world shifts toward lowering carbon emissions and supporting sustainability. Solar energy is one of the most promising renewable energy sources, and its harvesting potential has gone beyond typical solar panels to small, portable devices. Also, the trend toward smart buildings is becoming more prevalent at the same time as sensors and small devices are becoming more integrated, and the demand for dependable, sustainable energy sources will increase. Our work aims to tackle the issue of identifying the most suitable protective layer for small optical devices that can efficiently utilize indoor light sources. To conduct our research, we designed and tested a model that allowed us to compare the performance of many small panels made of monocrystalline cells laminated with three different materials: epoxy resin, an ethylene-tetrafluoroethylene copolymer (ETFE), and polyethylene terephthalate (PET), under varying light intensities from LED and CFL sources. The methods employed encompass contact angle measurements of the protective layers, providing insights into their wettability and hydrophobicity, which indicates protective layer performance against humidity. Reflection spectroscopy was used to evaluate the panels' reflectance properties across different wavelengths, which affect the light amount arrived at the solar cell. Furthermore, we characterized the PV panels' electrical behavior by measuring short-circuit current (ISC), open-circuit voltage (VOC), maximum power output (Pmax), fill factor (FF), and load resistance (R). Our findings offer valuable insights into each PV panel's performance and the protective layer material's effect. Panels with ETFE layers exhibited remarkable hydrophobicity with a mean contact angle of 77.7°, indicating resistance against humidity-related effects. Also, panels with ETFE layers consistently outperformed others as they had the highest open circuit voltage (VOC) ranging between 1.63-4.08 V, fill factor (FF) between 35.9-67.3%, and lowest load resistance (R) ranging between 11,268-772 KΩ.cm-2 under diverse light intensities from various light sources, as determined by our results. This makes ETFE panels a promising option for indoor energy harvesting, especially for powering sensors with low power requirements. This information could influence future research in developing energy harvesting solutions, thereby making a valuable contribution to the progress of sustainable energy technology.

Effect of Ionizing Radiation on Electrical Conductivity of a Tetrafluoroethylene–Ethylene Copolymer Containing Single-Wall Carbon Nanotubes

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Study of acoustic transmission losses in particle-reinforced rubber-based membrane-type acoustic metamaterials

In this work, the mechanical properties of particle reinforced ethylene propylene diene monomer (EPDM)/ethylene tetrafluoroethylene (ETFE) copolymer material were determined by molecular dynamics (MD) method, and the copolymer material was used in the structural design of acoustic metamaterials. Secondly, based on the discrete point matching method, the acoustic transmission loss characteristics of the material are predicted, and the accuracy and effectiveness of the theory are verified through the multi physical field coupling finite element model. Finally, seven key parameters that affect the material structure are studied, and their influencing rules and mechanisms are analyzed. The results show that the structure makes up for the sound insulation defect of traditional ETFE film materials at low frequencies. Through reasonable selection of key parameters, high sound insulation design can be carried out for specific frequency bands, which is of great significance to the potential application in the construction field (new building materials).

Non-isothermal crystallization kinetics of ethylene-tetrafluoroethylene copolymer using integral Avrami equation

Abstract The non-isothermal crystallization kinetics of ethylene-tetrafluoroethylene copolymer (ETFE, Fluon®C-88AXP) was studied by using differential scanning calorimetry (DSC). The Jeziorny, Ozawa, Mo, and Kissinger equations have been used to describe the crystallization data. The Ozawa and Kissinger plots show downward curves instead of the linear relationship as predicted. Good linear relationship was obtained using the Jeziorny and Mo equations but no vital model parameters concerned with the crystallization kinetics could be acquired. The integral Avrami equation combining with Hoffman equation has been used to describe the crystallization data through nonlinear regression method and kinetic parameters have been acquired. The fitting quality improves when the thermal lag effect was taken into consideration. Meanwhile, the linearity of the Ozawa and Kissinger analysis is improved greatly and the Ozawa exponent and crystallization activity energy of the copolymer have been obtained.

Effect of Radiation Crosslinking on the Yield Strength of a Carbon Fiber Reinforced Tetrafluoroethylene–Ethylene Copolymer

Effect of Radiation Crosslinking on the Yield Strength of a Carbon Fiber Reinforced Tetrafluoroethylene–Ethylene Copolymer

Effect of Aging on the Mechanical Properties of Highly Transparent Fluoropolymers for the Conservation of Archaeological Sites.

In recent years, fluoropolymers have found numerous applications in the architectural field because of their combination of mechanical-chemical resistance and high transparency. In the present work, commercial fluorinated polymers, such as perfluoro alkoxy (PFA) and ethylene tetrafluoroethylene copolymer (ETFE), have been evaluated for use as protective and transparent layers on monumental and archaeological sites (to preserve mosaics or frescoes) during the phases of restoration or maintenance outdoors. Considering this specific application, the present study was developed by evaluating the evolution of the mechanical (tensile, tear propagation resistance, and low-velocity impact tests) and chemical (FTIR and DSC analysis) properties of the films after accelerated UV aging. The results that were obtained demonstrated the high resistance capacity of the ETFE, which exhibits considerably higher elastic modulus and critical tear energy values than PFA films (1075.38 MPa and 131.70 N/mm for ETFE; 625.48 MPa and 59.06 N/mm for PFA). After aging, the samples exhibited only a slight reduction of about 5% in the elastic modulus for both polymers and 10% in the critical tear energy values for PFA. Furthermore, the differences in impact resistance after aging were limited for both polymers; however, the ETFE film showed higher peak force than the PFA films (82.95 N and 42.22 N, respectively). The results obtained demonstrated the high resistance capacity of ETFE films, making them the most suitable candidate for the considered application.

Efficient mineralization of ethylene-tetrafluoroethylene copolymer in superheated water with permanganate

Copolymer of ethylene and tetrafluoroethylene (ETFE) was treated in superheated water with KMnO4. ETFE efficiently decomposed to F– and CO2. Specifically, when ETFE (30 mg) was treated for 6 h with aqueous KMnO4 (52.7 mM; the molar amount was 1.7-fold excess of that of the fluorine atoms in ETFE) at 320 °C, the yields of F– and CO2 were 92 ± 1% and 73 ± 8%, respectively, and the total organic carbon content in the reaction solution was reduced to 4% of the carbon atom number in the initial ETFE. When the reactivity of ETFE was compared with that of poly(vinylidene fluoride) (PVDF), that is, an isomer of ETFE, ETFE required higher temperature to achieve mineralization. The present approach can reduce the reaction temperature allowing efficient mineralization of ETFE by 60 °C, compared to the previous method using supercritical water with dioxygen.

Surface functionalization of ethylene–tetrafluoroethylene copolymer film with poly(methyl methacrylate) via chemical radical polymerization

The surface of a poly(ethylene-co-tetrafluoroethylene) (ETFE) film was modified by grafting of methyl methacrylate (MMA) by using diethyl(1,10-phenanthroline N1,N10)zinc (Phen-DEZ) and oxygen molecules as the radical initiator. Fourier transform infrared (FT-IR) spectra and Raman spectra of polymethylmethacrylate-grafted-ETFE (ETFE-g-PMMA), showed absorption peaks attributed to carbonyl functionalities. And the thermal decomposition of ETFE-g-PMMA was observed in two stages. The first weight loss step was due to the disruption of the grafted PMMA polymer, while the second degradation step was likely due to thermal disruption of ETFE itself. These results provide clear evidence of PMMA grafting onto ETFE film. The grafting yield of MMA was found to be affected by the polymerization temperature, reaction time, and concentration of Phen-DEZ. Analysis of the surface morphology of the film by atomic force microscopy (AFM) suggests that MMA was grafted on the surface of the ETFE film. In addition, the water contact angle on the hydrophobic surface of the ETFE film changed from 94.6° to 65.5° depending on the graft of PMMA, resulting in hydrophilicity. Moreover, the results of the dyeing experiment showed that only the surface of the ETFE film was decorated with MMA and the interior was unchanged.

Irradiation, thermal and mechanical properties of ethylene-tetrafluoroethylene copolymer for use in wings of unmanned aerial vehicle

To study the properties of ethylene-tetrafluoroethylene (ETFE) copolymer materials in wings of unmanned aerial vehicles, electron beam irradiation was performed to prepare the corresponding irradiated ETFE for air atmosphere. All these irradiated samples were characterized by SEM, FTIR, TGA, DSC, flexural fatigue measurement and tensile test. The results revealed that the logarithm of the flexural fatigue of ETFE decreased with the irradiation dose increased, which could be explained by the growing effect of chain scission. The elongation-at-break decreased with the dose increase, while the tensile strength was kept constant. As shown in FTIR results, the scission of the macromolecular chains induced by irradiation resulted in the relative oxidation of groups, such as carbonyl groups. TGA analysis showed that the initial and maximum decomposition temperatures increased with dose increase due to the inherent cross-linking structures. Besides, the number of the crystalline regions with regular formation (such as crystallization temperature, crystallization degree and crystallization enthalpy) decreased with the dose increase as a result of the formation of unsaturated structures after the elimination of HF from the broken chains, which was confirmed by FTIR. It is expected that our findings can provide important information to promote the development of aircraft materials.

Effect of Radiation-Induced Cross-Linking on Thermal Aging Properties of Ethylene-Tetrafluoroethylene for Aircraft Cable Materials.

The effects of electron beam irradiation on ethylene-tetrafluoroethylene copolymer (ETFE) were studied. Samples were irradiated in air at room temperature by a universal electron beam accelerator for various doses. The effect of irradiation on samples and the cross-linked ETFE after aging were investigated with respect to thermal characteristics, crystallinity, mechanical properties, and volume resistivity using thermo-gravimetric analysis (TGA), differential scanning calorimeter (DSC), universal mechanical tester, and high resistance meter. TGA showed that thermal stability of irradiated ETFE is considerably lower than that of unirradiated ETFE. DSC indicates that crystallinity is altered greatly by cross-link. The analysis of mechanical properties, fracture surface morphology, visco-elastic properties and volume resistivity certify radiation-induced cross-linking is vital to aging properties.

Surface Engineering of Organic Polymers by Photo‐induced Free Radical Coupling with p‐Dimethylaminophenyl Group as A Synthesis Block

AbstractThis contribution presents a versatile strategy to transfer unactivated surface C–H bonds of polymeric substrates to C–R–F groups (R stands for a spacer and F stands for functional group) by UV light‐assisted surface free radical coupling. With p‐dimethylaminophenyl radical as a building block, various reactive groups, such as –CHO, –SH, –B(O)OH, –CN and –SO3−, are successfully grafted onto typical commercial polymer substrates including biaxially oriented polypropylene, polyethylene phthalate, ethylene tetrafluoroethylene copolymer and dimethyl silicone rubber. Fluorencence microscope images, X‐ray photoelectron spectroscopy, UV‐vis and fluorescence spectra support that the above functional groups are covalently bonded to the polymer substrates. The concentration of the reactive groups immobilized on the different substrates is in the order of 10−8 to 10−7 mmol mm−2 determined by UV‐vis spectrometry. In addition, as a proof‐of‐concept, the introduced functional groups are demonstrated by their special reactions, for example, –CHO reacting with –NH2 to synthesize Schiff base, –SH to detect silver ions, and the complexes of –C=N and Zn2+ to degrade Rhodamine B. The results indicate that one can fabricate an integrated molecular library on the surface of polymeric substrates at the molecular level by selecting the building blocks.

Fabrication of thermo-responsive cell-culture membranes with Poly(N-isopropylacrylamide) by electron-beam graft polymerization

Cell-sheet engineering aims to generate tissues and organs through lamination and transplantation of acquired cell sheets. The technique has become used in the field of regenerative medicine, and the development of cell-culture plates equipped with a switching function for cell adhesion/cell-sheet detachment has been in progress. Our research group has produced thermo-responsive cell-culture membranes by grafting poly(N-isopropylacrylamide) (PNIPAAm) onto an ethylene-tetrafluoroethylene copolymer (ETFE). Grafting is achieved via electron beam (EB) pre-irradiation grafting methods. The high biocompatibility of ETFE is well known, and high yields of trapped radicals can be obtained through the use of ionizing radiation. Increased thermo-responsivity of the cell-culture membranes can be achieved by increasing the amount of grafted PNIPAAm. In the present study, we fabricated grafted membranes with different grafting yields (GY), and evaluated the thermo-responsivity and cell-adhesion/cell-sheet-detachment abilities. First, C2C12 cells were cultured at 37°C for 2 days on the grafted samples, then the cell sheet was detached by reducing the temperature to 20°C after cell proliferation. In the fabricated samples with the GY of 14.9% ± 1.0%, cells reached confluence in 2 days, and the resulting cell sheet was detached within 15 min without any damage.

Promotion of poly(vinylidene fluoride) on thermal stability and rheological property of ethylene-tetrafluoroethylene copolymer

Abstract In this work, the thermal stability, rheological properties and mechanical properties of ethylene-tetrafluoroethylene copolymer (ETFE)/poly(vinylidene fluoride) (PVDF) blends were investigated by thermogravimetric analysis, rheometer and the tensile test. Thermal results indicated that blends had better thermal oxidation resistance than pure ETFE. Particularly, the initial thermal decomposition temperature (T d 0) and the temperature at maximum decomposition rate (T d max) of PVDF/ETFE (10/90 wt%) blends were at 374.49°C and 480°C, which were 52.6°C and 34°C higher than pure ETFE. The activation energy of thermal degradation (E d ) of ETFE was 66 kJ/mol, while the PVDF/ETFE (10/90 wt%) blends presented a higher E d , near 187 kJ/mol. Furthermore, rheological measurements demonstrated that the shear-thinning tendency of blends became stronger with increasing PVDF content. PVDF/ETFE (10/90 wt%) blends had somewhat lower mechanical properties than ETFE, which was still high enough for various applications. Blends with PVDF provided an efficient method to extend the application area of ETFE.

The formation of cross‐linking networks in a fluorinated polymer composite system by electron beam irradiation

AbstractIn this article, a cross‐linking network in poly(vinylidene fluoride) (PVDF)/poly(ethylene‐tetrafluoroethylene) copolymer (ETFE) blends was successfully created by electron beam irradiation. Thermal stability, mechanical properties, chemical structure, rheology properties, and crystallization behavior of irradiated samples were investigated. In particular, the PVDF/ETFE (10/90 wt%) blend irradiated with different dose exhibited better thermal stability and mechanical properties than pure ETFE. X‐ray photoelectron spectroscopy results demonstrated that the fluorinated composite system underwent cross‐linking and degradation reactions as a result of HF elimination and the formation of unsaturated structures and hydroperoxide species. Furthermore, the melting property of irradiated samples changed from liquid‐like behavior to pseudo‐solid‐like behavior. The degree of crystallinity of irradiated samples was found to increase at the range of 0–30 kGy and then clearly decreases with further increase in the irradiation dose. In general, our findings suggest that PVDF/ETFE blends treated with electron beam irradiation provide an opportunity to exploit their stability and durability for mechanically challenging applications.

Influence of Gamma-Irradiation and Thermal Annealing on Molecular–Topological Structure of Tetrafluoroethylene–Ethylene Copolymer

The molecular–topological structure of a tetrafluoroethylene copolymer with ethylene after γ-irradiation and thermal annealing has been studied. The pseudo-network structure of the copolymer contains, in addition to the amorphous block, crystalline segments of macromolecules in the role of branching sites. Topologically, the diblock structure of the copolymer after thermal annealing at 538 K is transformed into a three-block structure with the appearance of a high-temperature amorphous block. Irradiation of the copolymer with γ-rays to a dose of 150 kGy does not lead to appreciable changes in its molecular–topological structure.

Rheology and Foaming of Long-Chain Branched Ethylene-Tetrafluoroethylene Copolymer and Its Blends

Abstract The long-chain branched ethylene-tetrafluoroethylene copolymer (B-ETFE) was synthesized by radical polymerization using ethylene, tetrafluoroethylene, termonomer, and a very small amount of divinyl monomer. We studied melt rheology under shear and elongational flow, and foamability for B-ETFE, comparing with conventional linear ETFE. Addition of a small amount of the divinyl monomer had a considerable impact on the melt rheology of ETFE and its blends. The observed non-linear elongational behavior and emergence of long relaxation time components can be explained by long-chain branching in the modified ETFE. B-ETFE and its blends showed excellent foaming processability: uniform and smaller cell sizes and much higher cell number densities than those of linear ETFE. To the best of our knowledge, this is the first report of the enhancement of the melt rheology of ETFE from the viewpoint of modification of its molecular architecture.