| Broadband Electric Spectroscopy at High CO2 Pressure: Dipole Moment of CO2 and Relaxation Phenomena of the CO2-Poly(vinyl chloride) System. | |
| | |
MedLine Citation:
|
PMID: 21678893 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
Broadband Electric Spectroscopy (BES) is a technique that shows promise in studying the interactions of dense or supercritical gases with polymers, particularly with respect to chain mobility. Polymers that are treated with dense gases show a reduction in the viscosity, glass transition and melting temperature. A high pressure cell for BES has been constructed that can be used from ambient temperature and pressure to 353 K and 15 MPa and over a frequency range from 20 Hz to 1 MHz. In the past, the dielectric constant of CO2 was determined by measurements at only one or two frequency values. New instrumentation and technology allow this experiment to be expanded to cover a wider frequency range. BES measurements of CO2 show no relaxation peaks in the permittivity from 20 Hz to 1 MHz and 1 to 6 MPa. By these measurements, the CO2 dielectric constant was evaluated between 0.1 and 6MPa. Cell testing with poly(vinyl chloride) (PVC) at 323 K and CO2 pressures from 0.1 to 13 MPa indicate an increase in the chain segmental motion at high pressures resulting from a reduction in the glass transition temperature of the PVC-CO2 system due to plasticization by CO2. |
| | |
Authors:
|
Vito Di Noto; Keti Vezzu; Fosca Conti; Guinevere A Giffin; Sandra Lavina; Alberto Bertucco |
Related Documents
:
|
444913 - Hypopituitarism in normal-pressure hydrocephalus. 18653343 - Secondary intracranial hypertension with acute intracranial pressure crisis in superfic... 9887133 - Rate of nitric oxide production by lower alveolar airways of human lungs. |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2011-6-16 |
Journal Detail:
|
Title: The journal of physical chemistry. B Volume: - ISSN: 1520-5207 ISO Abbreviation: - Publication Date: 2011 Jun |
Date Detail:
|
Created Date: 2011-6-17 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 101157530 Medline TA: J Phys Chem B Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Proteomics based compositional analysis of complex cellulase-hemicellulase mixtures.
Next Document: Calf Thymus DNA-Binding Ability Study of Anthocyanins from Purple Sweet Potatoes ( Ipomoea batatas L...