Molecular Signatures of the Glass Transition in Polymers

04 May 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The glass transition temperature (Tg) is one of the most fundamental properties of polymers. Tg is predicted as a sudden change in a “macroscopic” quantity (e.g. compressibility). However, for systems with “soft” glass transitions where the change is gradual it becomes hard to pinpoint precisely the transition temperature as well as the set of molecular changes occurring during this transition. Here, we introduce two new molecular signatures for the glass transition of polymers that exhibit clear changes as one approaches Tg: i) differential change of the probability distribution of dihedral angles as a function of temperature, and ii) the distribution of fractional of time spent in the different torsional states. These new signatures provide insights into the glass transition in polymers by directly exhibiting the concept of spatial heterogeneity and dynamical ergodicity breaking in such systems, as well as provide a key step to quantitatively obtain the transition temperature from molecular characteristics of the polymeric systems.


glass transition

Supplementary materials

Supporting Information: Molecular Signatures of the Glass Transition in Polymers
Supporting information


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.