Enhancement of the crosslink density, glass transition temperature, and strength of epoxy resin by using functionalized graphene oxide co-curing agents

2016 ◽  
Vol 7 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Jin Won Yu ◽  
Jin Jung ◽  
Yong-Mun Choi ◽  
Jae Hun Choi ◽  
Jaesang Yu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Graphene Oxide ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
Crosslink Density ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Curing Agents

Epoxy nanocomposites are fabricated by using diamine-functionalized GO and exhibit high Tg, tensile strength, and crosslink density.

scholarly journals Studies on the Modification of Commercial Bisphenol-A-Based Epoxy Resin Using Different Multifunctional Epoxy Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Tensile Fracture ◽  
Chemical Structures ◽  
Amino Phenol ◽  
Epoxy Systems

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.

Effect of reduced graphene oxide on mechanical behavior of an epoxy adhesive in glassy and rubbery states

2021 ◽  
pp. 002199832110316
Author(s):  
Ata Khabaz-Aghdam ◽  
Bashir Behjat ◽  
EAS Marques ◽  
RJC Carbas ◽  
Lucas FM da Silva ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ambient Temperature ◽  
Mechanical Behavior ◽  
Reduced Graphene Oxide ◽  
Epoxy Adhesive ◽  
Ultimate Strain ◽  
Reduced Graphene

The mechanical behavior of an adhesive, in neat state and reinforced with up to 0.5 wt% of reduced graphene oxide (RGO) was investigated here. Tests were done at temperatures between the ambient temperature and the glass transition temperature ( Tg[Formula: see text] of the adhesive. Using a metal mold, cured plates of the neat and RGO reinforced epoxy adhesive were prepared. The adhesive powder and the bulk dumbbell-shaped specimens, obtained from cured adhesive plates, were subjected to differential scanning calorimetry (DSC) and tensile tests, respectively, to obtain the Tg as well as mechanical properties of the adhesives. The results indicated that adding RGO up to 0.5 wt% increased the glass transition temperature, the modulus of elasticity, and the strength of the adhesive. It was found that the presence of RGO reduced the adhesive’s strain at the break at the ambient temperature. However, at high temperatures, near the Tg, the ultimate strain of RGO-reinforced adhesives decreased slightly when compared to the ultimate strain of the neat specimens. This explains the reduction in toughness at ambient temperature obtained by adding RGO and the increase at high temperatures. Finally, the failure morphology of the neat and RGO-reinforced adhesive specimens was investigated using microscopic imaging of the specimens’ failure cross-sections, which supported and justified the experimental observations.

Experimental Research on Mechanical Behavior of GFRP Bars under High Temperature

2011 ◽  
Vol 71-78 ◽  
pp. 3591-3594 ◽  
Author(s):  
Xiao Lu Wang ◽  
Xiao Xiong Zha
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
High Temperatures ◽  
Glass Fibers ◽  
Ultimate Tensile Stress ◽  
Gfrp Bars ◽  
Tensile Test Result

Experimental results on tensile mechanics properties of GFRP bars at high temperatures are present in this paper. Thirty commercially produced GFRP tensile specimens of 8mm diameter were tested at high temperature ranging from 10°Cup to 500°C. Tensile test result indicates that, the ultimate tensile stress has significant reduction at two temperature zones, one is glass transition temperature of epoxy resin (80-120°C), with strength degradation 22%, the second is the soften temperature of glass fibers(about 400°C), the strength decrease drastically with almost linear rate and remained 33% residual strength at 500°C. The elastic modulus remained unchanged until glass transition temperature of epoxy resin, and the modulus declined linearly with the temperature elevating. Stress-strain relationships of GFRP bars exhibit liner performance even at high temperatures.

A facile way to prepare phosphorus-nitrogen-functionalized graphene oxide for enhancing the flame retardancy of epoxy resin

2018 ◽  
Vol 10 ◽  
pp. 97-102 ◽  
Author(s):  
Fang Fang ◽  
Pingan Song ◽  
Shiya Ran ◽  
Zhenghong Guo ◽  
Hao Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide

Influence of Carbon Nanotube Aspect Ratio on Glass Transition Temperature of Polymers: A Molecular Dynamics Simulation Study

2015 ◽  
Vol 817 ◽  
pp. 797-802 ◽  
Author(s):  
Cai Jiang ◽  
Jian Wei Zhang ◽  
Shao Feng Lin ◽  
Su Ju ◽  
Da Zhi Jiang
Keyword(s):  
Molecular Dynamics ◽  
Glass Transition ◽  
Carbon Nanotube ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Aspect Ratio ◽  
Epoxy Resin ◽  
Md Simulations ◽  
Diglycidyl Ether ◽  
Dynamics Simulation

Molecular dynamics (MD) simulations on three single walled carbon nanotube (SWCNT) reinforced epoxy resin composites were conducted to study the influence of SWCNT type on the glass transition temperature (Tg) of the composites. The composite matrix is cross-linked epoxy resin based on the epoxy monomers bisphenol A diglycidyl ether (DGEBA) cured by diaminodiphenylmethane (DDM). MD simulations of NPT (constant number of particles, constant pressure and constant temperature) dynamics were carried out to obtain density as a function of temperature for each composite system. The Tg was determined as the temperature corresponding to the discontinuity of plot slopes of the densityvsthe temperature. In order to understand the motion of polymer chain segments above and below the Tg, various energy components and the MSD at various temperatures of the composites were investigated and their roles played in the glass transition process were analyzed. The results show that the Tg of the composites increases with increasing aspect ratio of the embedded SWCNT

Viscoelastic behavior of an epoxy resin during cure below the glass transition temperature: Characterization and modeling

2018 ◽  
Vol 53 (2) ◽  
pp. 155-171 ◽  
Author(s):  
Alice Courtois ◽  
Martin Hirsekorn ◽  
Maria Benavente ◽  
Agathe Jaillon ◽  
Lionel Marcin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Strain History ◽  
Model Parameters ◽  
Degree Of Cure ◽  
Model Predictions

This paper presents a viscoelastic temperature- and degree-of-cure-dependent constitutive model for an epoxy resin. Multi-temperature relaxation tests on fully and partially cured rectangular epoxy specimens were conducted in a dynamic mechanical analysis apparatus with a three-point bending clamp. Master curves were constructed from the relaxation test results based on the time–temperature superposition hypothesis. The influence of the degree of cure was included through the cure-dependent glass transition temperature which was used as reference temperature for the shift factors. The model parameters were optimized by minimization of the differences between the model predictions and the experimental data. The model predictions were successfully validated against an independent creep-like strain history over which the temperature varied.

Nanocomposite Epoxy Resin for SiC Module

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000196-000200 ◽  
Author(s):  
Kenji Okamoto ◽  
Yuji Takematsu ◽  
Miyako Hitomi ◽  
Yoshinari Ikeda ◽  
Yoshikazu Takahashi
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
Molecular Motion ◽  
Experimental Results ◽  
Power Module ◽  
Operation Temperature ◽  
Thermal Stability Of

There is a demand to improve the thermal stability of epoxy molding resins used in the power module of SiC power chips operating at temperatures of 200°C or more. This paper describes a technique for increasing the thermal stability of the resin by decreasing molecular motion through the addition of nanofiller. The experimental results showed that the glass transition temperature (Tg) of the epoxy resin increased by approximately 30°C when the silica nanofiller was added. The epoxy resin added nanofiller was investigated in order to achieve the operation temperature 200°C of power module.

The effects of copper additives on the glass transition temperature and hardness for epoxy resin

2019 ◽  
Vol 13 (2) ◽  
pp. 163 ◽  
Author(s):  
Kareem A. Jasim ◽  
Rihab Nassr Fadhil ◽  
Auday H. Shaban ◽  
Harith I. Jaafar ◽  
Bushra K.H. Maiyaly ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin
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