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

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.

DEPENDENCE OF THE GLASS TRANSITION TEMPERATURE ON DENSITY IN A SOFT SPHERE SYSTEM WITH MORSE POTENTIAL

2002 ◽  
Vol 16 (18) ◽  
pp. 669-675
Author(s):  
HAO-YANG LIU ◽  
WEN-BING ZHANG ◽  
XIAN-WU ZOU ◽  
YIN-QUAN YUAN ◽  
ZHUN-ZHI JIN
Keyword(s):  
Molecular Dynamics ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Molecular Dynamics Simulation ◽  
Partition Function ◽  
Morse Potential ◽  
Function Analysis ◽  
Dynamics Simulation ◽  
Soft Sphere

The glass transition for the soft sphere system with Morse potential was investigated based on molecular dynamics simulation and partition function analysis. The dependence of the glass transition temperature on the density and the softness of the potential was obtained.

Molecular Dynamics Simulation on Compatibility and the Glass Transition Temperature of HTPB/Plasticizer Blends

2013 ◽  
Vol 718-720 ◽  
pp. 136-140 ◽  
Author(s):  
Lu Xia Yang ◽  
Lin Yu Mei ◽  
Yan Hua Lan ◽  
Li Qiong Liao ◽  
Yi Zheng Fu
Keyword(s):  
Molecular Dynamics ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Specific Volume ◽  
Md Simulation ◽  
Dibutyl Phthalate ◽  
Dioctyl Phthalate ◽  
Dynamics Simulation ◽  
Solubility Parameters

By means of full atomistic molecular dynamics (MD) simulation, the solubility parameters for hydroxyl-terminated polybutadiene (HTPB), dioctyl sebacate (DOS), dioctyl adipate (DOA), dibutyl phthalate (DBP), dioctyl phthalate (DOP), nitrated esters nitroglycerine (NG) and diethylene glycol dinitrate (DEGDN) are calculated and the results are in agreement with the literature values. Furthermore, in order to reveal the HTPB/plasticizer blend property, the specific volume vs. temperature curves of the blend systems are simulated by employing MD simulation to obtain the glass transition temperature (Tg). From the specific volume vs. temperature curve, the Tg of HTPB, HTPB/DOS, HTPB/DOA, HTPB/DBP, HTPB/DOP, HTPB/NG and HTPB/DEGDN are 197.54, 176.30, 183.11, 189.27,187.40, 200.03 and 205.31 K, respectively. It should be pointed out that as for HTPB and DOS, DOA, DBP, DOP, the solubility parameters are similar and there is only one glass transition of the blend system, these indicate that these studied blend systems are miscible, but HTPB/NG and HTPB/DEGDN are not miscible.

Effect of Chain Morphology and Carbon-Nanotube Additives on the Glass Transition Temperature of Polyethylene

2013 ◽  
Vol 23 ◽  
pp. 16-23 ◽  
Author(s):  
S. Herasati ◽  
H.H. Ruan ◽  
Liang Chi Zhang
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Glass Transition ◽  
Carbon Nanotube ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Md Simulation ◽  
Md Simulations ◽  
Crystalline Polymers ◽  
Good Agreement

Glass transition temperature Tg is the most important parameter affecting the mechanical properties of amorphous and semi-crystalline polymers. However, the atomistic origin of glass transition is not yet well understood. Using Polyethylene (PE) as an example, this paper investigates the glass transition temperature Tg of PE with the aid of molecular dynamics (MD) simulation. The effects of PE chain branches, crystallinity and carbon-nanotube (CNT) additives on the glass transition temperature are analyzed. The MD simulations render a good agreement with the relevant experimental data of semi-crystalline PE and show the significant effects of crystallinity and addition of CNTs on Tg.

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