A Frozen Tube Model of Melting Point Depression of Solvents in Entangled Polymer Systems

2003 ◽  
Vol 107 (7) ◽  
pp. 1483-1490 ◽  
Author(s):  
Yoshio Hoei ◽  
Yoshiyuki Ikeda ◽  
Muneo Sasaki
Keyword(s):  
Melting Point ◽  
Melting Point Depression ◽  
Tube Model ◽  
Polymer Systems ◽  
Entangled Polymer

Dynamics of Entangled Polymers

2015 ◽  
Author(s):  
Ronald G. Larson ◽  
Zuowei Wang
Keyword(s):  
Large Deformations ◽  
Nonlinear Viscoelasticity ◽  
Polymer Dynamics ◽  
Tube Model ◽  
Concentration Effects ◽  
Polymer Systems ◽  
Entangled Polymers ◽  
Entangled Polymer ◽  
Future Work ◽  
Entangled Polymer Solutions

This article explores the dynamics of entangled polymers, with particular emphasis on how the unusual and often dramatic mechanical properties of concentrated polymer systems are determined by the physics of entanglements. It begins with an overview of the foundations of entangled polymer dynamics, organized around tubes and slip links used in modeling entanglements, the packing length and concentration effects, the results of computer simulations on entanglements, topological contacts, and the effects of large deformations. The focus is on the nature of ‘entanglement’, both from a bottom-up molecular view, and from a phenomenological one. The discussion then turns to the linear viscoelasticity of entangled polymer solutions and melts, along with nonlinear viscoelasticity. Models of polymer dynamics in the linear regime are also described, including the ‘standard tube model’. The article concludes with suggestions for future work.

Analysis of Melting Point Depression of Benzene in Crosslinked Natural Rubber by a Frozen Tube Network Model

2005 ◽  
Vol 78 (5) ◽  
pp. 827-843 ◽  
Author(s):  
Y. Hoei
Keyword(s):  
Free Energy ◽  
Melting Point ◽  
Natural Rubber ◽  
Network Model ◽  
Melting Point Depression ◽  
Tube Model ◽  
Melting Thermodynamics

Abstract Literature reports from studies by Jackson and McKenna show a large difference in melting point depression between highly and lightly crosslinked (concentrated) natural rubber/benzene samples. Here, an equation for a tube model is developed to describe particularly the highly crosslinked mixtures at both swelling-and-melting equilibrium. On the basis of Flory-Huggins and Gibbs-Thomson equations, the model involves a swelling-and-melting thermodynamics that includes an elastic contribution to a free energy for a “real chain” network swollen in a good solvent. The freezing of the good solvent, then, occurs within the network chains which act as a confining (frozen) hard tube (having an unfrozen good solvent within). Consequently, the model can explain reasonably well the melting point depression of the highly crosslinked samples in the comparison of their estimates for crystallite (frozen tube) dimensions with certain corresponding literature values.

Melting point depression study of polyacrylonitrile

1960 ◽  
Vol 43 (142) ◽  
pp. 467-488 ◽  
Author(s):  
W. R. Krigbaum ◽  
Noboru Tokita
Keyword(s):  
Melting Point ◽  
Melting Point Depression

Standard enthalpy of fusion of N,N′-ethylenebis (2,4-pentanedion-iminoato)nickel(II) complex by DTA-based melting point depression studies

2005 ◽  
Vol 59 (11) ◽  
pp. 1334-1337 ◽  
Author(s):  
S. Arockiasamy ◽  
P. Antony Premkumar ◽  
O.M. Sreedharan ◽  
C. Mallika ◽  
V.S. Raghunathan ◽  
...  
Keyword(s):  
Melting Point ◽  
Standard Enthalpy ◽  
Enthalpy Of Fusion ◽  
Melting Point Depression

scholarly journals Determine Mesh Size through Monomer Mean-Square Displacement

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1405 ◽  
Author(s):  
Ji-Xuan Hou
Keyword(s):  
Main Parameter ◽  
Dynamic Method ◽  
Mean Square Displacement ◽  
Mesh Size ◽  
Step Length ◽  
Tube Diameter ◽  
Mean Square ◽  
Simulation Data ◽  
Polymer Systems ◽  
Entangled Polymer

A dynamic method to determine the main parameter of the tube theory through monomer mean-square displacement is discussed in this paper. The tube step length can be measured from the intersection of the slope- 1 2 line and the slope- 1 4 line in log-log plot, and the tube diameter can be obtained by recording the time at which g 1 data start to leave the slope- 1 2 regime. According to recent simulation data, the ratio of the tube step length to the tube diameter was found to be about 2 for different entangled polymer systems. Since measuring the tube diameter does not require g 1 data to reach the slope- 1 4 regime, this could be the best way to find the entanglement length from microscopic consideration.

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