scholarly journals Temperature dependence of methanol and the tensile strength of insulation paper: kinetics of the changes of mechanical properties during ageing

Cellulose ◽  
2016 ◽  
Vol 24 (2) ◽  
pp. 1031-1039 ◽  
Author(s):  
Oscar H. Arroyo ◽  
Jocelyn Jalbert ◽  
Issouf Fofana ◽  
Mohamed Ryadi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Temperature Dependence ◽  
Kinetics Of

scholarly journals Dynamic Cure Kinetics and Physical-Mechanical Properties of PEG/Nanosilica/Epoxy Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Haleh Nowruzi Varzeghani ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Solid Particles ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Cure Kinetic ◽  
Cure Temperature ◽  
Kinetics Of

This study investigated the effect of polyethylene glycol (PEG) and nanosilica (NS) on the physical-mechanical properties and cure kinetics of diglycidyl ether of bisphenol-A-based epoxy (DGEBA-based EP) resin. For this purpose, tensile and viscometry tests, dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC) were carried out under dynamic conditions. The results showed that adding NS and PEG enhances the maximum cure temperature as well as the heat of cure reaction (ΔH) in EP-NS, while it decreases in EP-PEG and EP-PEG-NS. The cure kinetic parameters of EP-PEG-NS were calculated by Kissinger, Ozawa, and KSA methods and compared with each other. The Ea calculated from the Kissinger method (96.82 kJ/mol) was found to be lower than that of the Ozawa method (98.69 kJ/mol). Also, according to the KAS method, the apparent Ea was approximately constant within the 10-90% conversion range. Tensile strength and modulus increased by adding NS, while tensile strength diminished slightly by adding PEG to EP-NS. The glass transition temperature (Tg) was calculated using DMTA which was increased and decreased by the addition of NS and PEG, respectively. The results of the viscometry test showed that the viscosity increased with the presence of both PEG and NS and it prevented the deposition of solid particles.

scholarly journals The effect of drying on the mechanical properties and structure of biodegradable films

2018 ◽  
Author(s):  
Gabriela Silveira da Rosa ◽  
Sai Vanga ◽  
Yvan Gariepy ◽  
Vijaya Raghavan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Convective Drying ◽  
Vacuum Drying ◽  
Drying Rate ◽  
Biodegradable Films ◽  
Film Forming ◽  
Rate Period ◽  
Bovine Gelatin ◽  
Kinetics Of

The aim of this study was to investigate the effect of convective and vacuum drying on properties of biodegradable films. The film-forming solutions were prepared with bovine gelatin and carrageenan. The films solutions were dried in convective and vacuum dryers at temperatures of 40, 50 and 60 oC. The results of convective drying kinetics of biofilms showed a constant drying rate period followed by a falling drying rate period. The results of thickness showed dependence with moisture content present in films.Carrageenan films showed promising results, with high values of tensile strength and elongation for convective drying at 60 oC. Keywords: gelatin; carrageenan; drying; biofilm 

Mechanical Properties of a β Containing Ti-Al-Cr-Alloy at Ambient and Elevated Temperatures

1994 ◽  
Vol 364 ◽  
Author(s):  
W. R. Chen ◽  
J. Wang ◽  
B. Zhang ◽  
X. Wan ◽  
W. J. Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ambient Temperature ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Elevated Temperatures ◽  
High Tensile Strength ◽  
Tial Alloys ◽  
Β Phase ◽  
Very High

AbstractThe mechanical properties of a β-containing Ti-Al-Cr alloy were investigated at ambient and elevated temperatures. The results show that the Ti-Al-Cr alloy containing the β phase has a very high tensile strength but a poor ductility at ambient temperature, and that higher ductility is obtained at high temperatures. The temperature dependence of mechanical properties is found to be sensitive to the strain rate during the test. Fractography shows that the fracture mode changes from fully brittle to ductile-brittle mixture with the increased temperature. All the results suggest that the triple-phased TiAl alloys (α2+β+γ) may have the combined mechanical properties of the dual-phased T13Al ((α2+β) and dual-phased TiAl (α2+γ) alloys.

Microstructure and Mechanical Properties of Mg-Gd-Y Alloy

2011 ◽  
Vol 71-78 ◽  
pp. 3329-3332
Author(s):  
Ke Jie Li
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Crack Propagation ◽  
Temperature Dependence ◽  
Anomalous Temperature Dependence ◽  
Anomalous Temperature ◽  
Critical Crack ◽  
T6 Heat Treatment ◽  
Casting Technology

The Mg-12Gd-2Y-0.5Sm-0.5Sb-0.5Zr (wt.%) alloy was prepared by casting technology. The microstructure of alloy was then investigated after T6 heat treatment. The results show that at 523K, the alloy has shown the superior tensile strength (i.e. 345.5 MPa). When experimental alloy was stretched with temperature increasing from 293K to 523K, the increases of deformation strengthening and critical crack propagation stress caused the anomalous temperature dependence of tensile strength.

Kinetics and Optimum Phenomenon of Vulcanization

1947 ◽  
Vol 20 (4) ◽  
pp. 933-937
Author(s):  
B. Dogadkin ◽  
B. Karmin ◽  
I. Golberg
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Point Of View ◽  
Sulfur Monochloride ◽  
Physical Chemical ◽  
Fundamental Process ◽  
Technical Properties ◽  
Kinetics Of ◽  
Homogeneous Reactions

Abstract The fundamental process of vulcanization consists in the combination of rubber with a vulcanizing agent : sulfur, sulfur monochloride, etc. The kinetics of this process may be expressed by monotonous curves. These may be interpreted either as the result of the heterogeneous character of the reaction or as the result of the combination of several homogeneous reactions. At the same time that the rubber combines with the vulcanizing agent, and largely as a consequence of this, a number of its physical-chemical and mechanical properties—solubility, density, tensile strength and other properties—undergo a change. These changes are extremely interesting from the technological point of view. In distinction to the kinetics of the combination of rubber with the vulcanizing agent, the kinetics of these processes can in most cases be represented by curves with a maximum or minimum. Thus, in the vulcanization of crude rubber, the tensile strength and modulus change according to a curve having a maximum; the solubility change follows a curve with a minimum. This character of the change experienced by the principal technical properties of the rubber determines the so-called “vulcanization optimum”. This term refers to that moment in the process of vulcanization when the particular property attains the necessary maximum or minimum, depending on the technical purposes of the vulcanizate.

Dependence of the Ultimate Properties of a SBR Rubber on Strain Rate and Temperature

1959 ◽  
Vol 32 (4) ◽  
pp. 992-1004 ◽  
Author(s):  
Thor L. Smith
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Temperature Dependence ◽  
Amorphous Polymers ◽  
Shift Factor ◽  
Ultimate Properties ◽  
Tensile Data ◽  
Small Deformations

Abstract The tensile strength and ultimate elongation of polymeric materials depend on both the temperature and experimental time scale. The mechanical properties of amorphous polymers at temperatures above their glass transition temperature Tg are more amenable to treatment in terms of molecular theories than are their mechanical properties at temperatures below Tg or the mechanical properties of crystalline polymers. For amorphous polymers at temperatures above Tg the viscoelastic properties in small deformations have been studied rather extensively, and several molecular theories—essentially identical—have been published. In contrast, few systematic studies have been made of the effect of time and temperature on the ultimate properties. Consequently, only a limited amount of data is available which can serve as a basis for developing and verifying molecular theories dealing with ultimate properties. A recent theory by F. Bueche treats the time and temperature dependence of tensile strength. According to his theory, the tensile strength for a given material is a universal function of a reduced time or a reduced strain rate, except at short times or high strain rates where the material approaches glasslike behavior. Also, to superpose data measured at different temperatures, a shift factor is needed which is determined by the temperature dependence of the frictional factor for polymeric segment mobility and thus is the same factor as used to superpose viscoelastic data measured in small deformations. Thus, according to Bueche's theory, the temperature dependence of the tensile strength is given by the equation of Williams, Landel, and Ferry which is applicable in the temperature range Tg<T<(Tg+100). Bueche reported some tensile data for polybutyl methacrylate which has a glass transition temperature of 8° C. These tensile data were measured under various constant loads at temperatures between 30 and 95° C, and reasonable agreement between theory and experiment was found. Although Bueche did not consider the ultimate elongation, it seems reasonable that such data can be superposed by using the same shift factor as required to superpose the tensile strength data. Other workers have not considered explicitly the effect of viscous forces on the ultimate properties but have considered the effect of such variables as molecular weight, degree of crosslinking, and plasticizers.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽  
2000 ◽  
Vol 49 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Kaiser Aluminum ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

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