Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Influence of cohesive energy on relaxation in a model glass-forming polymer melt



Jack F. Douglas, Wensheng Xu, Karl Freed


The wide range of chemical compositions exhibited by polymer materials leads to materials having highly tunable cohesive energy strength epsilon, and many of the properties that make polymers so useful as structural and responsive materials in manufacturing and in living systems derive from this basic property. The problem of polymer materials design and characterization then inevitably leads to a consideration of how epsilon impacts the thermodynamic and relaxation properties of polymer liquids. Our initial paper systematically investigated the epsilon dependence of commonly measured thermodynamic properties of a model coarse-grained polymer melt by molecular dynamics simulation, while the present work focuses on the relaxation dynamics of the same model. After demonstrating that greatly influences the segmental relaxation time, as expected, we obtain a universal reduction of all our relaxation data in terms of an activated transport model in which the activation free energy is increased from its high temperature value by a factor precisely determined by the average extent of monomer cooperative motion in the polymer liquid.


Douglas, J. , Xu, W. and Freed, K. (2016), Influence of cohesive energy on relaxation in a model glass-forming polymer melt, Macromolecules (Accessed April 23, 2024)
Created November 8, 2016, Updated January 27, 2020