Positron annilation lifetime and glass transition temperatures in CO 2 sorption polystyrene

Y. C. Jean, H. Chen, L. J. Lee, J. Yang

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Positron annihilation lifetime spectroscopy was used to measure the free-volume size and distributions as a function of temperature in polystyrene with and without 400 psi CO2 sorption. The transition temperatures in the polystyrene with CO2 sorption obtained from ortho-positronium lifetimes were found to depend on the thermal cycles and a meta-stable state showing a negative thermal expansion coefficient was observed between 53°C and 82°C during the first heating up experiment. The observed Tg in polystyrene with, and without CO2 sorption after annealing from ortho-positronium lifetimes were found to be 86°C and 91°C, which are 5°C higher, and 10°C lower than from the differential scanning calorimetry data, respectively. The observed free-volume variations are discussed in terms of hole expansion, creation, free-volume relaxation, plasticization, and hole filling in amorphous polymers.

Original languageEnglish
Pages (from-to)1385-1395
Number of pages11
JournalActa Physica Polonica A
Volume113
Issue number5
DOIs
StatePublished - May 2008

Fingerprint

Dive into the research topics of 'Positron annilation lifetime and glass transition temperatures in CO 2 sorption polystyrene'. Together they form a unique fingerprint.

Cite this