Conformational transition characterization of glass transition behavior of polymers

Wu, Rongliang; Kong, Bin; Yang, Xiaozhen

doi:10.1016/j.polymer.2009.05.013

Cited by 20 publications

(53 citation statements)

References 54 publications

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“…42 By using the single-molecule uorescence microscopy, Wöll's group found that the temperature dependence of fraction of mobile molecules in polystyrene lms exhibited similar trends with that of PSM. [26][27][28][29][30][31][32] Similarly, we also observe the conformational changes during cooling in the current simulation. [26][27][28][29][30][31][32] Similarly, we also observe the conformational changes during cooling in the current simulation.…”

Section: Resultsmentioning

confidence: 60%

“…13,14 For instance, the structural characteristics of CRR are still unknown. [27][28][29][30][31][32] The increase of the fraction of transconformations may induce the formation of the short-range order in polymers. For colloidal system, Tanaka et al 23,24 and Yodh et al 25 detected the formation of some local ordered structures during cooling, and they argued that the development of the local ordered structures may be the origin of the slow dynamics.…”

Section: Introductionmentioning

confidence: 99%

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Structural characteristics of a cooperatively rearranging region during the glass transition of a polymer system

Nie

Zhou

et al. 2015

RSC Adv.

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The correlations between local ordered structures and cooperative motion were investigated by dynamic Monte Carlo (MC) simulation. The fraction of trans-conformation increases with the decrease of temperature, indicating the occurrence of a conformational transition from gauche-to transconformations. Due to the relatively high degree of close-packing, the trans-conformations are inclined to form local order. Furthermore, all the segments in the polymer system can be divided into two types: the ordered and the disordered ones. Compared with the ordered segments, the disordered segments have more neighboring vacancy sites, and thus move faster and randomly. Correspondingly, the segments in the local order have fewer neighboring vacancy sites, and exhibit lower mobility, which could only move cooperatively along the parallel direction. Those findings suggest that the cooperatively rearranging regions proposed by Adam and Gibbs contain more local ordered structures.

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Section: Resultsmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Structural characteristics of a cooperatively rearranging region during the glass transition of a polymer system

Nie

Zhou

et al. 2015

RSC Adv.

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“…At the glass transition temperature, the specific volume, v , versus temperature, T , exhibits a change in slope, moving from a low value in the glassy state ( T < T g ) to a higher value in the rubbery state ( T > T g ) . Molecular dynamics can be used to determine the specific volume of the polymer at different temperatures, at a constant pressure.…”

Section: Theorymentioning

confidence: 99%

“…MD simulation has been previously used to determine glass transition temperatures of engineering polymers such as polypropylene, polyimides, and poly(aryl‐ether‐ether‐ketone) . In this method, glass transition is usually identified by (i) changes in the temperature coefficients of the density, the free volume, or any of the energy components of the force field; (ii) vanishing of the self‐diffusion coefficient associated with the polymer chains (iii) a decrease in the conformational transitions of the chains on cooling the system through the glass transition temperature (iv) change in heat capacity near glass transition, and (v) structural relaxations …”

Section: Introductionmentioning

confidence: 99%

Simulated Dilatometry and Static Deformation Prediction of Glass Transition and Mechanical Properties of Polyacetylene and Poly(para‐phenylene vinylene)

Venkatanarayanan

Krishnan

Sreeram

et al. 2016

Macro Theory & Simulations

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Thermophysical and mechanical properties of two conjugated polymers, poly(p‐phenylene vinylene) (PPV) and polyacetylene (PA), are predicted using molecular dynamics simulations and compared with results obtained from differential scanning calorimetry, nanoindentation, and dynamic mechanical analysis experiments. Glass transition temperature (Tg) is calculated from the changes in the slopes of the specific volume versus temperature and cohesive energy density versus temperature plots, obtained from constant pressure and constant temperature simulations (NPT ensemble). The effects of temperature on the torsion angle distributions and characteristic ratio are analyzed. PPV is found to have a Tg of 416 ± 8 K. PA does not exhibit a glass transition in the temperature range of 120 to 500 K. Using the static deformation method, the values of Young's modulus are calculated to be 1.81 ± 0.34 GPa for PA and 9.20 ± 0.57 GPa for PPV at 298 K. These values are in good agreement with the experimental measurements, validating the suitability of these techniques in the prediction of the polymer properties.

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“…The energy of the system was minimized using Forcite Model and Compass forcefield. The Compass forcefield is a powerful force field for the simulation calculations of atomic level on the condensed materials, which was adopted by many researchers . The 20 chains, each containing 60 repeat units, were used to construct amorphous cell by the experimental density at 300 K and 1 atm.…”

Section: Models and Simulation Detailsmentioning

confidence: 99%

Temperature Dependence of Structural Properties and Chain Configurational Study: A Molecular Dynamics Simulation of Polyethylene Chains

Zhou

Hao

et al. 2015

Macro Theory & Simulations

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Micro-structural evolution of polyethylene (PE) across the glass transition temperature (T g ) is investigated by full atom molecular dynamic (MD) simulation. The specific volume as a function of temperature for PE is obtained, through which the volumetric glass transition temperature was determined. The dihedral distribution of the overall bonds of the amorphous polyethylene chain system keeps consistent with the rotational isomeric state scheme. The dependence of isomer probability of skeletal bonds and average radius of gyration on temperature also can be used to estimate the glass temperature. The micro-structural information obtained from MD simulation should be helpful to understand glass transition mechanism of polymer system.

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Conformational transition characterization of glass transition behavior of polymers

Cited by 20 publications

References 54 publications

Structural characteristics of a cooperatively rearranging region during the glass transition of a polymer system

Structural characteristics of a cooperatively rearranging region during the glass transition of a polymer system

Simulated Dilatometry and Static Deformation Prediction of Glass Transition and Mechanical Properties of Polyacetylene and Poly(para‐phenylene vinylene)

Temperature Dependence of Structural Properties and Chain Configurational Study: A Molecular Dynamics Simulation of Polyethylene Chains

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