Uniaxial deformation and orientation of ethylene–tetrafluoroethylene films

Focatiis, Davide S.A. De; Gubler, Lorenz

doi:10.1016/j.polymertesting.2013.09.007

Cited by 36 publications

(21 citation statements)

References 43 publications

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“…For the values, the range values defined as the difference between the maximum and minimum values and the dimensionless ratio of the range value to the maximum value are 3.2-18.8 MPa and 82.9% for temperature tests while those are 14.7-18.2 MPa and 19.2% for loading speed tests, meaning that the effect of temperature on first yield stress is greater than that of loading speed when considering the normal working conditions. This finding is in line with conclusion in [12]. In view of the yield stress for structural analysis, linear equations under the loading speed and temperature conditions are given in Fig.…”

Section: Yield Stress and Elastic Modulussupporting

confidence: 91%

“…For ETFE foils, conventional methods to determine these mechanical properties are the geometric methods for the yield stress [10] and simple linear fitting of the stress-strain curve for the elastic modulus [22]. The two yield stresses are defined as the stress values at the intersections of three distinct tangents through the stress-strain curve [12] and two elastic moduli are obtained by the tangent and secant fitting [8,10]. These methods could be affected by small deviation of the tangents.…”

Section: Mathematical Methods For Determining Mechanical Propertiesmentioning

confidence: 99%

“…A survey of the literature shows that many researchers have paid their attention to investigate the mechanical properties of ETFE foils, such as tensile strength, breaking strain, yield stress and elastic modulus. For example, Chen et al [7], Wu et al [8], Moritz [9,10], Galliot and Luchsinger [11] and De Focatiis and Gubler [12] investigated parts or all uniaxial tensile mechanical properties of ETFE foils under loading speed conditions. Moritz [9,10], Lee et al [13], Wang et al [14], De Focatiis and Gubler [12] determined the mechanical properties under a wide range of temperatures.…”

Section: Introductionmentioning

confidence: 99%

“…For example, Chen et al [7], Wu et al [8], Moritz [9,10], Galliot and Luchsinger [11] and De Focatiis and Gubler [12] investigated parts or all uniaxial tensile mechanical properties of ETFE foils under loading speed conditions. Moritz [9,10], Lee et al [13], Wang et al [14], De Focatiis and Gubler [12] determined the mechanical properties under a wide range of temperatures. Moreover, some papers on cyclic tests [9,15] and creep tests [16,17] are available for ETFE foils.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Uniaxial tensile mechanical properties and model parameters determination of ethylene tetrafluoroethylene (ETFE) foils

Chen

Zhao

et al. 2015

Construction and Building Materials

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Section: Yield Stress and Elastic Modulussupporting

confidence: 91%

Section: Mathematical Methods For Determining Mechanical Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Uniaxial tensile mechanical properties and model parameters determination of ethylene tetrafluoroethylene (ETFE) foils

Chen

Zhao

et al. 2015

Construction and Building Materials

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“…Radiation grafting cations results in a reduction of all mechanical properties compared to the ETFE precursor film that has high modulus (520-570 MPa), strength (150-200 MPa), and elongation (350-550%). 40 Increasing the temperature from 30…”

Section: Etfe-g-pvbtmamentioning

confidence: 99%

Mechanical Characterization of Anion Exchange Membranes by Extensional Rheology under Controlled Hydration

Vandiver

Caire

Carver

et al. 2014

J. Electrochem. Soc.

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Alkali anion exchange membrane (AEM) based devices have the potential for electrochemical energy conversion using inexpensive catalysts and a variety of fuel types. Membrane stability and anion transport must be improved in AEMs before these devices can be fully realized. Mechanical failure of the membrane can contribute to failure of the device, thus membrane durability is critical to overall system design. Here, a study of the mechanical properties of three well-established AEMs uses a modified extensional rheometer platform to simulate tensile testing using small membrane samples. Mechanical properties were tested at 30 and 60 • C under dry or water saturated gas conditions. Water in the membrane has a plasticizing effect, softening the membrane and reducing strength. PEEK membrane reinforcement limits swelling producing negligible softening and only a 9% decrease in strength from dry to hydrated conditions at 30 • C. Higher cation concentration increases water uptake resulting in significant softening, a 57% reduction in Young's modulus, and a 67% reduction in strength when hydrated at 30 • C. In a working electrochemical device, AEMs must maintain integrity over a range of temperatures and hydrations, making it critical to considering mechanical properties when designing new membranes. Polymer electrolyte membrane fuel cells and electrolyzers are potentially disruptive technologies that will replace traditional heat engines such as internal combustion engines for transportation applications, portable electronics, and are scalable to larger energy storage facilities. Polymer electrolyte membrane fuel cells are suitable for transportation applications due to their low temperature start-up and operation, high power density, and quick refueling.1-3 Proton exchange membranes (PEMs) have dominated polymer electrolyte membrane fuel cell development in the last several decades, resulting in the development of relatively stable, well performing membranes.1-4 Current PEM fuel cells remain cost prohibitive due to high catalysts costs, as well as long-term durability issues. 3,5,6 Anion exchange membranes (AEMs) can also be utilized in polymer electrolyte membrane devices and have several potential benefits over PEMs. AEM fuel cells benefit from increased kinetics in an alkali media allowing more complex fuels then hydrogen and have the potential to utilize non-platinum catalysts to reduce costs. 7-11However, a number of challenges must be overcome before AEMs reach the performance and durability necessary for fuel cells and other electrochemical energy conversion devices. Hydroxide present in the AEM degrades many of the proposed cationic groups and some polymer backbones, making development of chemically stable AEMs difficult. 9,11,12 Additionally, transport of hydroxide in AEMs is inherently slower than protons in PEMs, 13 to compensate, the concentration of ionic groups is often increased in AEMs.8 Increasing ion concentration in AEMs increases water sorption in the polymer and can result in significant dimensional...

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Polymer Design Strategies for Radiation‐Grafted Fuel Cell Membranes

Gubler

2013

Advanced Energy Materials

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In the past decade, fuel cell technology has been moving steadily towards commercialization, with prospects of high production volumes, in particular in electric vehicle applications. However, the cost and durability of the currently‐used materials and components fall short of the requirements for large‐scale industrialization. The development of alternative, more cost‐effective materials with competitive performance and durability attributes is therefore ongoing. Radiation‐induced graft copolymerization (“radiation grafting”) is a versatile method to modify pre‐existing polymers to introduce a variety of desired functionalities, such as ion‐exchange capacity. Here, an overview of fundamentals and recent developments in the area of radiation grafted ion‐conducting polymers for application in polymer electrolyte fuel cells (PEFCs) is provided. Key aspects of polymer design are discussed, taking into consideration the radiation chemistry of base polymer materials and the adequate choice of grafting monomers for different PEFC types. Furthermore, the current status of applications in fuel cells is highlighted.

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Uniaxial deformation and orientation of ethylene–tetrafluoroethylene films

Cited by 36 publications

References 43 publications

Uniaxial tensile mechanical properties and model parameters determination of ethylene tetrafluoroethylene (ETFE) foils

Uniaxial tensile mechanical properties and model parameters determination of ethylene tetrafluoroethylene (ETFE) foils

Mechanical Characterization of Anion Exchange Membranes by Extensional Rheology under Controlled Hydration

Polymer Design Strategies for Radiation‐Grafted Fuel Cell Membranes

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