Molecular Dynamics Simulations of the Glass Transition Temperature of Amorphous Cellulose

2012 ◽  
Vol 214 ◽  
pp. 7-11 ◽  
Author(s):  
Xiu Mei Zhang ◽  
M.A. Tschopp ◽  
Sheldon Q. Shi ◽  
Jun Cao
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Specific Volume ◽  
Reasonable Agreement ◽  
Reactive Force ◽  
Time Step ◽  
Amorphous Cellulose ◽  
Dynamics Simulations ◽  
Insight Into

Molecular modeling and dynamics simulations were used to generate equation of state properties of amorphous cellulose with the reactive force field ReaxFF which has been extensively parameterized and validated for hydrocarbon in a previous communication. Obtaining specific volume as a function of temperature for amorphous cellulose, the change in slope of the specific volume vs. temperature curves can be used to locate glass transition temperatures (Tg) reliably. With the results, there was reasonable agreement between experimental results and values of density and Tg obtained from the simulations. In addition, the suitable ReaxFF time step was investigated to help conserve the total energy of the system. The results show that the glass transition temperature can be used to verify the equilibration of the amorphous cellulose and to provide insight into the further deformation simulations.

Influence of lithium perchlorate on the properties of polyether networks: specific volume and glass transition temperature

1988 ◽  
Vol 21 (4) ◽  
pp. 1117-1120 ◽  
Author(s):  
Jean Francois Le Nest ◽  
Alessandro Gandini ◽  
Herve Cheradame ◽  
Jean Pierre Cohen-Addad
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Specific Volume ◽  
Lithium Perchlorate

Prediction of the glass transition temperature and design of phase diagrams of butadiene rubber and styrene–butadiene rubber via molecular dynamics simulations

2017 ◽  
Vol 19 (25) ◽  
pp. 16498-16506 ◽  
Author(s):  
Myung Shin Ryu ◽  
Hyoung Gyu Kim ◽  
Hyun You Kim ◽  
Kyung-Shin Min ◽  
Hak Joo Kim ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Molecular Dynamics Simulations ◽  
Phase Diagrams ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Dynamics Simulations ◽  
Styrene Butadiene

In this study, we developed an equation to evaluate the pseudo-ternary Tg of quaternary SBR and plotted the ternary contour Tg plot for SBR with a variety of styrene compositions.

scholarly journals Combined light- and heat-induced shape memory behavior of anthracene-based epoxy elastomers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuzhan Li ◽  
Monojoy Goswami ◽  
Yuehong Zhang ◽  
Tuan Liu ◽  
Jinwen Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Shape Memory ◽  
Uv Light ◽  
Dynamic Mechanical Properties ◽  
Stimuli Responsive ◽  
Epoxy Monomer ◽  
Dynamics Simulations ◽  
External Stimuli

AbstractThe development of multi-stimuli-responsive shape memory polymers has received increasing attention because of its scientific and technological significance. In this work, epoxy elastomers with reversible crosslinks are synthesized by polymerizing an anthracene-functionalized epoxy monomer, a diepoxy comonomer, and a dicarboxylic acid curing agent. The synthesized elastomers exhibit active responses to both light and heat enabled by the incorporated anthracene groups. When exposed to 365 nm UV light, additional crosslinking points are created by the photo-induced dimerization of pendant anthracene groups. The formation of the crosslinking points increases modulus and glass transition temperature of the elastomers, allowing for the fixation of a temporary shape at room temperature. The temporary shape remains stable until an external heat stimulus is applied to trigger the scission of the dimerized anthracene, which reduces the modulus and glass transition temperature and allows the elastomers to recover their original shapes. The effects of external stimuli on the thermal and dynamic mechanical properties of the elastomers are investigated experimentally and are correlated with molecular dynamics simulations that reveal the changes of structure and dynamics of the anthracene molecules and flexible chains.

scholarly journals Numerical Simulation of the Viscohyperelastic Behaviour of PET near the Glass Transition Temperature

2012 ◽  
Vol 504-506 ◽  
pp. 1139-1144
Author(s):  
Yun Mei Luo ◽  
Luc Chevalier ◽  
Eric Monteiro
Keyword(s):  
Numerical Simulation ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Biaxial Tension ◽  
Green Tensor ◽  
Biaxial Testing ◽  
Time Step ◽  
Moulding Process ◽  
Non Linear

The presentation deals with the non linear strongly elastic and viscous behaviour of poly ethylene terephthalate near the glass transition temperature and biaxially stretched at high strain rates representative of the injection stretch blow moulding process. A non linear visco-hyperelastic model inspired from [1] and identified from the experimental results of the equi-biaxial tension test [2], have been developed and presented in [3] is implemented into a finite element code developed with Matlab. The thermal behaviour modelling, identification and simulation has also been managed. First, a numerical simulation of 2D plane stress case has been performed involving 2 fields (global velocity V and elastic Cauchy Green tensor Be). Rectangular finite elements with quadratic and linear interpolations have been employed for velocity and the elastic left Cauchy Green tensor. Second, an axi symmetric formulation involving 4 fields (global velocity V, lagrange multiplier p associated with the global incompressibility condition, and multiplier q associated with the incompressibility of the elastic part) has been performed using rectangular elements. Degree of interpolation have been tested for all possible combinations to test the LBB like condition. Both simulations are compared with equi biaxial or sequential biaxial testing in order to reproduce the strain hardening effect and the self-heating observed. The final goal of this work is to perform the free blowing simulation to compare with experimental data. Therefore, we should solve an iterative procedure for a thermo-mechanical equation. At each time step, a four-field approach is adopted for the mechanical part, and a classical heat transfer equation is discretised for the thermal part.

Glass transition of ion-containing polymer melts in bulk and thin films

Soft Matter ◽  
2021 ◽  
Vol 17 (37) ◽  
pp. 8420-8433 ◽  
Author(s):  
Wei Li ◽  
Monica Olvera de la Cruz
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Molecular Dynamics Simulations ◽  
Polymer Melts ◽  
Transition Behavior ◽  
Dynamics Simulations

We investigate the glass transition behavior of ion-containing polymers via molecular dynamics simulations, revealing its coupling with ionic correlations as well as variations of the glass transition temperature in bulk and thin films.

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