Thermomechanical properties of silica–epoxy nanocomposite modified by hyperbranched polyester: A molecular dynamics simulation

2021 ◽  
pp. 095400832110323
Author(s):  
Jianwen Zhang ◽  
Dongwei Wang ◽  
Lujia Wang ◽  
Wanwan Zuo ◽  
Xiaohua Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Glass Transition ◽  
Epoxy Resin ◽  
Silica Surface ◽  
Thermomechanical Properties ◽  
Dynamics Simulation ◽  
Hyperbranched Polyester ◽  
Pure Epoxy ◽  
Epoxy Nanocomposite

In this article, pure epoxy resin and silica–epoxy nanocomposite models were established to investigate the effects of hyperbranched polyester on microstructure and thermomechanical properties of epoxy resin through molecular dynamics simulation. Results revealed that the composite of silica can improve the thermomechanical properties of nanocomposites, including the glass transition temperature, thermal conductivity, and elastic modulus. Moreover, the thermomechanical properties were further enhanced through chemical modification on the silica surface, where the effectiveness was the best through grafting hyperbranched polyester on the silica surface. Compared with pure epoxy resin, the glass transition temperature of silica–epoxy composite modified by silica grafted with hyperbranched polyester increased by 38 K. The thermal conductivity increased with the increase of temperature and thermal conductivity at room temperature increased to 0.4171 W/(m·K)−1 with an increase ratio of 94.3%. Young’s modulus, volume modulus, and shear modulus all fluctuated as temperature rise with a down overall trend. They increased by 44.68%, 29.52%, and 36.65%, respectively, when compared with pure epoxy resin. At the same time, the thermomechanical properties were closely related to the microstructure such as fractional free volume (FFV), mean square displacement (MSD), and binding energy. Silica surface modification by grafting hyperbranched polyester reduced the FFV value and MSD value most and strengthened the combination of silica and epoxy resin matrix the best, resulting in the best thermomechanical properties.

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

Dopamine-modified nanographite as reinforcing filler for epoxy nanocomposite

2018 ◽  
Vol 53 (12) ◽  
pp. 1671-1679
Author(s):  
Jun Song ◽  
Zhendong Dai ◽  
Feng Nan ◽  
Jingyu Li ◽  
Haichao Zhao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Epoxy Resin ◽  
Photoelectron Spectroscopy ◽  
Mechanical Analysis ◽  
Test Results ◽  
Pure Epoxy ◽  
Epoxy Nanocomposite ◽  
Transmission Electron ◽  
Complementary Role

A biomimetic dopamine chemistry was employed to enhance the dispersibility of nanographite in epoxy resin. The as-prepared polydopamine (PDA)-coated nanographite were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy, respectively. Epoxy/nanographite nanocomposites were prepared by curing reaction of epoxy E44, Jeffamine D-230 and polydopamine-coated nanographite. Nanocomposites with different nanographite loadings (0.5%, 1%, 2%) were characterized by thermogravimetric analysis, dynamic mechanical analysis, tribological and thermal conductivity test. Results of thermal analysis showed that nanographite somewhat enhanced the thermal stability in comparison with the pure epoxy resin. Compared to pure epoxy resin, the as-prepared nanocomposites exhibited improved thermal, mechanical and wear-resistant performance, which was attributed to the complementary role of mechanical and thermal conductivity of nanographite.

scholarly journals Effect of Aminosilane Coupling Agents with Different Chain Lengths on Thermo-Mechanical Properties of Cross-Linked Epoxy Resin

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 951 ◽  
Author(s):  
Yujing Tang ◽  
Chao Tang ◽  
Dong Hu ◽  
Yingang Gui
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
Silica Particles ◽  
Dynamics Simulation ◽  
Nano Silica ◽  
Chain Lengths

In this paper, a molecular dynamics simulation method was used to study the thermo-mechanical properties of cross-linked epoxy resins doped with nano silica particles that were grafted with 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-[2-(2-aminoethylamino)ethylamino]-propyl-trimethoxysilane with different chain lengths. Firstly, a set of pure epoxy resin models, and four sets of SiO2/EP composite models were established. Then, a reasonable structure was obtained through a series of optimizations using molecular dynamics calculations. Next, the mechanical properties, hydrogen bond statistics, glass transition temperature, free volume fraction, and chain spacing of the five models were studied comparatively. The results show that doped nano silica particles of surfaces grafted with 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-[2-(2-aminoethylamino)ethylamino]-propyl-trimethoxysilane with different chain lengths enhanced mechanical properties such as elastic modulus, shear modulus, and volume modulus obviously. The glass transition temperature increased by 15–16 K, 40–41 K, and 24–27 K, respectively. Finally, the data show that the cross-linked epoxy resin modified by nanoparticles grafted with N-(2-aminoethyl)-3-aminopropyl trimethoxysilane had better effects for improving thermo-mechanical properties by the comparatively studying the five groups of parameter models under the same conditions.

Designing high thermal conductivity of cross-linked epoxy resin via molecular dynamics simulations

2020 ◽  
Vol 22 (35) ◽  
pp. 19735-19745
Author(s):  
Ran Huo ◽  
Zhiyu Zhang ◽  
Naveed Athir ◽  
Yanhao Fan ◽  
Jun Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Molecular Dynamics Simulations ◽  
Epoxy Resin ◽  
High Thermal Conductivity ◽  
Dynamics Simulation ◽  
Coarse Grained ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

Coarse-grained (CG) non-equilibrium molecular dynamics simulation was used to study the thermal conductivity of a cross-linked network composed of epoxy resin (E51) and polyether amine (PEA).

Study of lattice thermal conductivity of tungsten containing bubbles by molecular dynamics simulation

2020 ◽  
Vol 161 ◽  
pp. 112004
Author(s):  
Hongyu Zhang ◽  
Jizhong Sun ◽  
Yingmin Wang ◽  
Thomas Stirner ◽  
Ali Y. Hamid ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Lattice Thermal Conductivity ◽  
Dynamics Simulation

scholarly journals Preparation and Thermal Conductivity of Epoxy Resin/Graphene-Fe3O4 Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2013
Author(s):  
Zhong Wu ◽  
Jingyun Chen ◽  
Qifeng Li ◽  
Da-Hai Xia ◽  
Yida Deng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Epoxy Resin ◽  
Thermomechanical Properties ◽  
Packaging Materials ◽  
Mass Ratio ◽  
Degree Of Orientation ◽  
Ep Matrix ◽  
Electrical Insulation Properties

By modifying the bonding of graphene (GR) and Fe3O4, a stable structure of GR-Fe3O4, namely magnetic GR, was obtained. Under the induction of a magnetic field, it can be orientated in an epoxy resin (EP) matrix, thus preparing EP/GR-Fe3O4 composites. The effects of the content of GR and the degree of orientation on the thermal conductivity of the composites were investigated, and the most suitable Fe3O4 load on GR was obtained. When the mass ratio of GR and Fe3O4 was 2:1, the thermal conductivity could be increased by 54.8% compared with that of pure EP. Meanwhile, EP/GR-Fe3O4 composites had a better thermal stability, dynamic thermomechanical properties, and excellent electrical insulation properties, which can meet the requirements of electronic packaging materials.

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