scholarly journals Investigation of the curing process of epoxy compositions by developed amine products based on household waste polyethylene terephthalate and polycarbonate

2021 ◽  
pp. 21-24
Author(s):  
M. B. Alikin ◽  
K. D. Alekseeva ◽  
D. A. Panfilov ◽  
N. A. Lavrov ◽  
I. M. Dvorko
Keyword(s):  
Polyethylene Terephthalate ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Aliphatic Amine ◽  
Gelation Time ◽  
Structural Features ◽  
Household Waste ◽  
Curing Process ◽  
Waste Polyethylene ◽  
Epoxy Groups

The objects of research are oligomers-hardeners obtained by aminolysis of secondary polyethylene terephthalate (PET) and polycarbonate (PC) household waste with an aliphatic amine (PEP).The epoxy-diane resin of the ED-20 brand was chosen as the binder cured by the obtained oligomers due to its availability, good properties, acceptable viscosity, and wide applicability. The study of some parameters of the curing of thermosetting resin by industrial and synthesized hardeners is carried out.The gelation times at elevated temperatures (in the range from 50 to 100°C) and the activation energies of epoxy compositions were determined, and the conversion of epoxy groups during curing at room temperature was studied. The analysis of the obtained data showed that the structural features of macromolecules caused by the introduction of PET and PC fragments have a negligible effect on the activation energy and affect only when cured at room temperature and increase the viability of the compositions, while the gelation time at elevated temperatures in the case of all the studied hardeners is almost the same.

Curing Process of Epoxy Resin Using Low Molecular Polyamide 651 as Curing Agent

2014 ◽  
Vol 936 ◽  
pp. 63-66 ◽  
Author(s):  
Chun Hua Han ◽  
Lin Wang ◽  
Dong Yu Zhao
Keyword(s):  
Epoxy Resin ◽  
Room Temperature ◽  
Curing Agent ◽  
Curing Process ◽  
Curing Conditions ◽  
Temperature Spectra ◽  
Infrared Spectral ◽  
Ft Ir ◽  
Ir Analysis ◽  
Epoxy Groups

In this paper low molecular polyamide 651(PA651) is used as the curing agent of epoxy resin. The optimum curing conditions and dosage of the curing agent are obtained by DMA and FT-IR analysis. Based on the dynamic mechanical temperature spectra of samples test, the best curing conditions are room temperature 2 hours, 70°C 2 hours, 125°C 2.5 hours and 150°C 1 hours (RT / 2 h + 70 °C / 2 h +125°C / 2.5 h + 150 °C / 1 h). The best dosage of curing agent PA651 is 50 wt %. Since the analysis of Fourier Infrared spectral verified that epoxy groups react completely, the curing conditions are the best curing process.

The Effect of Si(IV) Species Derived from Chitosan-Silicate Hydrogels on Osteoblast Behavior

2011 ◽  
Vol 493-494 ◽  
pp. 698-702 ◽  
Author(s):  
Yuki Shirosaki ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka
Keyword(s):  
Cell Adhesion ◽  
Room Temperature ◽  
Gelation Time ◽  
Osteoblastic Cells ◽  
Amino Groups ◽  
Hybrid Hydrogels ◽  
Methoxy Groups ◽  
Gelation Behavior ◽  
Epoxy Groups ◽  
Phosphate Groups

Chitosan-GPTMS (γ-Glycidoxypropyltrimethoxysilane) hybrid hydrogels were synthesized with β-glycerophosphate (β-GP) as the additive agent. Chitosan-GPTMS sols were fluid at room temperature and transformed to hydrogel at 36.5°C in several min. The gelation time of the hydrogels was shortened by the addition of GPTMS. From NMR experiments, this gelation behavior depended on some factors, namely, electrostatic interaction between the phosphate groups of β-GP and the amino groups of chitosan chains, crosslinking between the epoxy groups of GPTMS and the amino groups of chitosan, and polycondensation of the methoxy groups of GPTMS. The Si(IV) released from the hydrogels promoted the cell adhesion and ALP activity of osteoblastic cells MG63.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Spherulite Structures in a Melt Spun Fe-Ni Austenitic Steel

1985 ◽  
Vol 43 ◽  
pp. 52-53
Author(s):  
G. M. Michal ◽  
T. K. Glasgow ◽  
T. J. Moore
Keyword(s):  
Austenitic Steel ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Large Range ◽  
Amorphous Structure ◽  
Nucleation And Growth ◽  
Ni Alloys ◽  
Melt Spun ◽  
Crystal Fibers ◽  
Rapidly Solidified

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

Strong Coupling: Polariton Bose Condensation

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Strong Coupling ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Dissipative System ◽  
Bose Condensation ◽  
Einstein Condensation ◽  
Strong Coupling Regime ◽  
Stimulated Scattering ◽  
Exciton Polaritons ◽  
Bose Einstein

In this Chapter we address the physics of Bose-Einstein condensation and its implications to a driven-dissipative system such as the polariton laser. We discuss the dynamics of exciton-polaritons non-resonantly pumped within a microcavity in the strong coupling regime. It is shown how the stimulated scattering of exciton-polaritons leads to formation of bosonic condensates that may be stable at elevated temperatures, including room temperature.

Utilization of air-plasma treated waste polyethylene terephthalate particles as a raw material for particleboard production

2016 ◽  
Vol 90 ◽  
pp. 188-194 ◽  
Author(s):  
Petr Klímek ◽  
Tomáš Morávek ◽  
Jozef Ráhel ◽  
Monika Stupavská ◽  
David Děcký ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Raw Material ◽  
Air Plasma ◽  
Waste Polyethylene

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

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