Effect of chemical structure on the isobaric and isochoric fragility in polychlorinated biphenyls
- 1 April 2005
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 122 (13), 134505
- https://doi.org/10.1063/1.1863173
Abstract
Pressure-volume-temperature data, along with dielectric relaxation measurements, are reported for a series of polychlorinated biphenyls (PCB), differing in the number of chlorine atoms on their phenyl rings. Analysis of the results reveals that with increasing chlorine content, the relaxation times of the PCB become governed to a greater degree by density rho relative to the effect of temperature T. This result is consistent with the respective magnitudes of the scaling exponent gamma yielding superpositioning of the relaxation times measured at various temperatures and pressures, when plotted versus rho(gamma)/T. While at constant (atmospheric) pressure, fragilities for the various PCB are equivalent, the fragility at constant volume varies inversely with chlorine content. Evidently, the presence of bulkier chlorine atoms on the phenyl rings magnifies the effect which the density has on the relaxation dynamics.Keywords
This publication has 87 references indexed in Scilit:
- Effects of the volume and temperature on the global and segmental dynamics in poly(propylene glycol) and 1,4‐polyisopreneJournal of Polymer Science Part B: Polymer Physics, 2004
- Evolution of the Dynamics in 1,4-Polyisoprene from a Nearly Constant Loss to a Johari−Goldstein β-Relaxation to the α-RelaxationMacromolecules, 2004
- Investigation of the correlation between structural relaxation time and configurational entropy under high pressure in a chlorinated biphenylThe Journal of Chemical Physics, 2002
- A New Vogel-Like Law: Ionic Conductivity, Dielectric Relaxation, and Viscosity near the Glass TransitionPhysical Review Letters, 2001
- High frequency relaxation of o-terphenylThe Journal of Chemical Physics, 1995
- Mechanical and Dielectric Spectroscopy of Aroclor, 1,2-Polybutadiene, and Their MixturesMacromolecules, 1995
- 13C NMR Study of Component Dynamics in Aroclor/Poly(vinylethylene) MixturesMacromolecules, 1995
- Segmental relaxation in blends of polychloroprene and epoxidized polyisopreneMacromolecules, 1994
- Anomalous reduction of solvent friction in chlorinated biphenyl solutions of 1,2-polybutadienePhysical Review B, 1992
- Translational and rotational diffusion in supercooled orthoterphenyl close to the glass transitionZeitschrift für Physik B Condensed Matter, 1992