TEMPERATURE-DEPENDENCE OF MOLECULAR MOTIONS IN BULK POLYSTYRENE

TitleTEMPERATURE-DEPENDENCE OF MOLECULAR MOTIONS IN BULK POLYSTYRENE
Publication TypeJournal Article
Year of Publication1994
AuthorsBlackburn, F. R., M. T. Cicerone, and M. D. Ediger
JournalJournal of Polymer Science Part B-Polymer PhysicsJournal of Polymer Science Part B-Polymer PhysicsJournal of Polymer Science Part B-Polymer Physics
Volume32
Pagination2595-2604
Date PublishedDec
Type of ArticleArticle
ISBN Number0887-6266
Accession NumberWOS:A1994PU61000005
KeywordsDEPOLARIZATION, DIELECTRIC-RELAXATION, DYNAMICS, GLASS-RUBBER RELAXATION, LABELED-CHAIN DYNAMICS, LOCAL POLYMER, PHOTON-CORRELATION SPECTROSCOPY, POLYISOPRENE, PROBE ROTATION, PROBE TRANSLATION, REORIENTATION, ROTATIONAL, SEGMENTAL DYNAMICS, TETRAHYDROFURAN, TIME-RESOLVED OPTICAL SPECTROSCOPY, TRANSITION, VISCOSITY
Abstract

Time-resolved optical spectroscopy is used to investigate the reorientation of three rigid probes and one labeled chain in bulk polystyrene. Orientational correlation times for these probes and labels are found to be in the range of 10(-8)-10(-10) s at temperatures of 180-300 degrees C. Consistent with previous studies, the attachment of a chromophore into the chain backbone slows its dynamics by about an order of magnitude. The temperature dependences of the correlation times are similar to the temperature dependence of the viscosity. When combined with probe reorientation times near and below T-g, these results indicate that probe reorientation tracks the temperature dependence of the viscosity quite well over twelve decades in time. In contrast, literature results for the translational diffusion of similarly sized probes indicates a substantially weaker temperature dependence near T-g. Thus it appears that a fundamental change in the mechanism of probe motion occurs near T-g. (C) 1994 John Wiley and Sons, Inc.

Short TitleJ. Polym. Sci. Pt. B-Polym. Phys.J. Polym. Sci. Pt. B-Polym. Phys.
Alternate JournalJ. Polym. Sci. Pt. B-Polym. Phys.