Research on Heat Resisting Epoxy Resin System for Liquid Composite Molding

2015 ◽  
Vol 1101 ◽  
pp. 8-14
Author(s):  
Qing Qing Wu ◽  
Jia Yu Xiao ◽  
Jun Liu ◽  
Su Li Xing ◽  
Jing Shui Yang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Heat Resistance ◽  
Epoxy Resin ◽  
Resistance Testing ◽  
Liquid Composite Molding ◽  
Resin System ◽  
Epoxy Resin System ◽  
Composite Molding

The properties of heat resistance and manufacturability of epoxy resin system are contradictory to each other. In order to maintain the balance of both properties, this article studied the heat resistance (testing the glass-transition temperature using differential scanning calorimetry) and the manufacturability (characterizing the variation trend of viscosity at molding temperature using AR2000EX rotational rheometer) of two kinds of epoxy resin systems by means of designing orthogonal table. Studies show that when the mass ratio of hydantoin epoxy resin, MF-4101 epoxy resin, anhydride and accelerant is 100:20:150:1.5, the glass transition temperature of the epoxy resin system can reach over 180°C. What’s more, the initial viscosity of the epoxy resin at 40°C is about 230mPa•s, and the viscosity can maintain no more than 800mPa•s in approximately 3 hours, which meets the requirements of liquid composite molding.

Durability Studies of Hybrid Composite of E-Glass/Carbon Fibers in Different Solvents for Bridge Deck Panel Application

2014 ◽  
Author(s):  
Peter Owuor ◽  
Alfred Tcherbi-Narteh ◽  
Mahesh Hosur ◽  
Shaik Jeelani
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Epoxy Resin ◽  
Storage Modulus ◽  
Flexural Properties ◽  
Resin System ◽  
Glass Transition Temperatures ◽  
Solvent Uptake ◽  
Epoxy Resin System ◽  
Glass Carbon

Objective An experimental study was carried out to investigate the solvent uptake in E-glass/Carbon Fiber composites with two types of epoxy systems: SC-15 and 635 epoxy resins in water, saltwater and antifreeze. These resins were infused into carbon, E glass and a hybrid of carbon and E-glass fabrics. Unconditioned samples with 635 epoxy resin system showed better flexural properties in case of both carbon fiber and hybrid composites but poor response when used as a matrix for E-glass fibers compared to SC-15 epoxy resin. Flexural properties for conditioned samples were determined after an immersion period of 8 weeks at room temperature and results showed that the 635 epoxy resin has a poor retention of flexural properties compared to SC-15 epoxy resin with highest degradation recorded for samples fabricated using E-glass fabrics. Moisture absorption curves did not follow the Fick’s law of diffusion except for first week of immersion. Lowest solvent uptake was recorded in antifreeze while highest was recorded in saltwater. Low operation temperature was exhibited by 635 epoxy resin with lower values of glass transition temperature compared to SC-15 epoxy resin. Storage modulus and glass transition temperatures determined from dynamic mechanical analysis (DMA) showed that composites with 635 epoxy resin system had better storage modulus while those with SC-15 had higher glass transition temperatures. Highest degradation in storage modulus was seen in E-glass-635 epoxy samples when conditioned with salt water while the maximum reduction in the glass transition temperature was seen for E-glass-635 epoxy samples conditioned with water.

scholarly journals Toughening studies on an ABS/PC blend-modified epoxy resin system

1994 ◽  
Vol 6 (3) ◽  
pp. 241-248 ◽  
Author(s):  
K Natarajan ◽  
R M V G K Rao
Keyword(s):  
Fracture Toughness ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
Diglycidyl Ether ◽  
Particle Dispersion ◽  
Scanning Electron Micrographs ◽  
Epoxy Resin System ◽  
Modified Epoxy

Studies were carried out on the toughening of a bifunctional epoxy (diglycidyl ether of bisphenol-A) matrix system with an ABS/PC thermoplastic blend. The thermoplastic blend was incorporated into the epoxy matrix by particle dispersion and melt-mix methods. The unmodified and modified epoxy resin systems were cured with a stoichiometric quantity of diamino diphenyl methane (DDM). The cured castings were characterized by measurement of glass transition temperature (Tg) by DsC, evaluation of plane strain fracture toughness (Klc) by three-point bending tests and SEM analysis of non-etched and base/acid etched fracture surfaces. In genera] ABS/PC-modified (15% w/w) epoxy-resin-cured systems showed enhanced fracture toughness without lowering the glass transition temperature. The melt-mix method yielded higher fracture toughness than the particle dispersion method; this conclusion was also supported by scanning electron micrographs.

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.

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.

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

The Effects of Chemical Resistance for Nanocomposite Materials via Nano-Silica Addition into Glass Fiber/Epoxy

2013 ◽  
Vol 853 ◽  
pp. 28-33
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen ◽  
Kung Liang Lin ◽  
Bor Kae Chang
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Storage Modulus ◽  
Chemical Resistance ◽  
Dynamic Mechanical Properties ◽  
Silica Nanopowder

Nanocomposite samples containing epoxy resin, glass fiber and 0~2 wt.% SiO2 nanopowder are prepared. The effects of SiO2 addition on the chemical resistance, glass transition temperature (Tg) and dynamic mechanical properties of the various samples are then observed. The chemical resistance of the nanocomposite specimens is compared with that of pure glass fiber/epoxy composite specimens when tested in acetone. The results show that the addition of 2 wt.% SiO2 increases the value of storage modulus by 1646MPa compared to that of the sample containing no silica nanopowder. Following immersion in acetone, all the nanocomposite specimen storage modulus decreased, but the addition of SiO2 reduced the decline, where the 2 wt. % samples decrease from 11.76% reduction to 0.84% and no significant change in the Tg compared to that of the sample with no silica nanopowder. Therefore, the experimental results indicate that 2 wt.% SiO2 addition is beneficial in improving chemical resistance, glass transition temperature, and dynamic mechanical properties of epoxy resin / glass fiber nanocomposites.

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