Characterization of moisture effect on static and fatigue performance of epoxy resin using thin-film specimen on dynamic mechanical analyzer

2016 ◽  
Vol 51 (3) ◽  
pp. 303-314 ◽  
Author(s):  
Yuanchen Huang ◽  
Yunpeng Zhu ◽  
Carlos Alberto Cimini ◽  
Sung Kyu Ha
Keyword(s):  
Thin Film ◽  
Epoxy Resin ◽  
Water Immersion ◽  
Thick Layer ◽  
Fatigue Tests ◽  
Dynamic Mechanical Analyzer ◽  
Moisture Effect ◽  
Dynamic Mechanical ◽  
Dog Bone ◽  
Film Specimen

A novel method of characterizing moisture effect on mechanical performance of epoxy resin is presented in this paper. A 50-µm-thick layer of cured epoxy resin was fabricated and cut into strips of 4 mm wide and 30 mm long as specimens to be tested on a dynamic mechanical analyzer equipped with thin-film tension clamp. Static tension and force-controlled tension–tension fatigue tests were first carried out using thin-film specimens made from Momentive 135/137 and BASF 5400/5440 epoxy resin systems without applying moisture, and results were compared with those obtained using conventional dog-bone specimens to validate the proposed testing method. Another batch of thin-film specimens were then immersed into deionized water, and the weight gain was recorded regularly until full saturation to obtain the absorption curve. Static and fatigue tests were performed using thin-film specimens made from BASF 5400/5440 with 55% and 100% saturation of moisture respectively, to evaluate moisture-induced material degradation. The aging effect on BASF 5400/5440 caused by cyclic water immersion and drying process was also assessed by performing static and fatigue tests using fully dried thin-film specimens after aging. It was concluded that the combination of thin-film specimen and dynamic mechanical analyzer would yield as good measurements of tensile strength and fatigue life as conventional dog-bone specimen does, and the small thickness of thin-film specimen would greatly reduce the time to reach a certain level of moisture content, facilitating further studies on effect of moisture ingression on polymeric matrix composites using multi-scale approaches.

Low-cycle fatigue tests of zirconium alloys using a dynamic mechanical analyzer

2013 ◽  
Vol 48 ◽  
pp. 187-191 ◽  
Author(s):  
S.A. Nikulin ◽  
V.A. Markelov ◽  
A.Yu. Gusev ◽  
T.A. Nechaykina ◽  
A.B. Rozhnov ◽  
...  
Keyword(s):  
Low Cycle Fatigue ◽  
Zirconium Alloys ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Dynamic Mechanical Analyzer ◽  
Dynamic Mechanical

scholarly journals Thermal and Dielectric Properties of Cyanate Ester Cured Main Chain Rigid-Rod Epoxy Resin

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2917
Author(s):  
Chi-Ping Li ◽  
Chih-Min Chuang
Keyword(s):  
Dielectric Properties ◽  
Epoxy Resin ◽  
Mechanical Analysis ◽  
Diglycidyl Ether ◽  
Cyanate Ester ◽  
Dynamic Mechanical Analyzer ◽  
Dynamic Mechanical ◽  
Thermogravimetric Analyzer ◽  
Rigid Rod ◽  
Phase Temperature

Thermal and dielectric properties of rigid-rod bifunctional epoxy resin 4,4-bis(2,3-epoxypropoxy) biphenyl epoxy (BP) and commercial epoxy resin diglycidyl ether of bisphenol A (DGEBA) were studied using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), dynamic mechanical analyzer (DMA), thermal mechanical analyzer (TMA) and dielectric analyzer (DEA). These two epoxies were cured with cyanate ester hardener 2,2’-bis(4-cyanatophenyl) propane (AroCy B10). The BP/B10 system consisting of a rigid-rod structure exhibited better thermal properties than the DGEBA/B10 system with a flexible structure. Anisotropic BP/B10 (2:1) had the highest 5% weight loss temperature, the highest amount of residue and a smaller thermal expansion coefficient than the commercial DGEBA/B10 system. The BP/B10 system, which cured at the LC phase temperature, had higher Tg than the commercial DGEBA/B10 system, as found from dynamic mechanical analysis. The BP/B10 system also demonstrated better dielectric properties than the commercial DGEBA/B10 system when enough curing agent was provided.

Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study

1967 ◽  
Vol 25 ◽  
pp. 366-367
Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
High Altitude ◽  
Amyl Acetate ◽  
Temperature Variations ◽  
Film Forming ◽  
Film Specimen ◽  
Particulate Contaminants

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.

scholarly journals Dynamic mechanical behaviors of epoxy resin/hollow polymeric microsphere composite foams under forced non-resonance and forced resonance

2021 ◽  
Vol 30 ◽  
pp. 263498332110081
Author(s):  
Rui Li ◽  
Guisen Fan ◽  
Xiao Ouyang ◽  
Guojun Wang ◽  
Hao Wei
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Second Order ◽  
Polymer Microspheres ◽  
Hollow Glass Microsphere ◽  
Dynamic Mechanical ◽  
First Order ◽  
Composite Foams ◽  
Prepared Composite ◽  
Loss Factors

Composite foams with 10–50 vol% hollow polymeric microspheres were prepared using bisphenol A epoxy resin and polyetheramine curing agent as the matrix. The results demonstrated that the density, hardness, and static mechanical properties of the epoxy resin/hollow polymer microsphere composite foams, as well as their dynamic mechanical properties under forced non-resonance, were similar to those of polymer/hollow glass microsphere composite foams. At 25°C and under 1–100 Hz forced resonance, the first-order and second-order resonance frequencies of the composite foams shifted to the low-frequency region as the volume fraction of hollow polymer microspheres increased. Meanwhile, the first-order and second-order loss factors of the as-prepared composite foams were improved by 41.7% and 103.3%, respectively, compared with the pure epoxy resin. Additionally, the first-order and second-order loss factors of the as-prepared composite foams reached a maximum at 40 vol% and 30 vol% hollow polymer microspheres, respectively. This research helps us to expand the application range of composite foam materials in damping research.

scholarly journals Multiscale Characterization of E-Glass/Epoxy Composite Exposed to Extreme Environmental Conditions

2021 ◽  
Vol 5 (3) ◽  
pp. 80
Author(s):  
George Youssef ◽  
Scott Newacheck ◽  
Nha Uyen Huynh ◽  
Carlos Gamez
Keyword(s):  
Power Distribution ◽  
Epoxy Composite ◽  
Fire Retardant ◽  
Sandwich Composite ◽  
Dynamic Mechanical Analyzer ◽  
Fire Event ◽  
Balsa Wood ◽  
X Ray ◽  
Dynamic Mechanical ◽  
Composite Skins

Fiber-reinforced polymer matrix composites continue to attract scientific and industrial interest since they offer superior strength-, stiffness-, and toughness-to-weight ratios. The research herein characterizes two sets of E-Glass/Epoxy composite skins: stressed and unstressed. The stressed samples were previously installed in an underground power distribution vault and were exposed to fire while the unstressed composite skins were newly fabricated and never-deployed samples. The mechanical, morphological, and elemental composition of the samples were methodically studied using a dynamic mechanical analyzer, a scanning electron microscope (SEM), and an x-ray diffractometer, respectively. Sandwich composite panels consisting of E-glass/Epoxy skin and balsa wood core were originally received, and the balsa wood was removed before any further investigations. Skin-only specimens with dimensions of ~12.5 mm wide, ~70 mm long, and ~6 mm thick were tested in a Dynamic Mechanical Analyzer in a dual-cantilever beam configuration at 5 Hz and 10 Hz from room temperature to 210 °C. Micrographic analysis using the SEM indicated a slight change in morphology due to the fire event but confirmed the effectiveness of the fire-retardant agents in quickly suppressing the fire. Accompanying Fourier transform infrared and energy dispersive X-ray spectroscopy studies corroborated the mechanical and morphological results. Finally, X-ray diffraction showed that the fire event consumed the surface level fire-retardant and the structural attributes of the E-Glass/Epoxy remained mainly intact. The results suggest the panels can continue field deployment, even after short fire incident.

scholarly journals Tunable Perfect THz Absorber Based on a Stretchable Ultrathin Carbon-Polymer Bilayer

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 143 ◽  
Author(s):  
Alesia Paddubskaya ◽  
Marina Demidenko ◽  
Konstantin Batrakov ◽  
Gintaras Valušis ◽  
Tommi Kaplas ◽  
...  
Keyword(s):  
Thin Film ◽  
Metal Film ◽  
Sandwich Structure ◽  
Thick Layer ◽  
Pyrolytic Carbon ◽  
Thz Radiation ◽  
Pdms Film ◽  
Absorption Resonance ◽  
Screen Approach ◽  
Polymer Thickness

By exploring the Salisbury screen approach, we propose and demonstrate a thin film absorber of terahertz (THz) radiation. The absorber is comprised of a less than 100 nm thick layer of pyrolytic carbon deposited on a stretchable polydimethylsiloxane (PDMS) film followed by the metal film. We demonstrate that being overall less than 200 microns thick, such a sandwich structure absorbs resonantly up to 99.9%of the incident THz radiation, and that the absorption resonance is determined by the polymer thickness, which can be adjusted by stretching.

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