Dye reorientation as a probe of stress-induced mobility in polymer glasses

TitleDye reorientation as a probe of stress-induced mobility in polymer glasses
Publication TypeJournal Article
Year of Publication2008
AuthorsLee, H. N., K. Paeng, S. F. Swallen, and M. D. Ediger
JournalJournal of Chemical Physics
Volume128
Pagination134902
ISBN Number0021-9606
Accession NumberWOS:000254778800056
KeywordsAMORPHOUS POLYMERS, DEFORMATION, ENHANCED TRANSLATIONAL DIFFUSION, PLASTICITY, POLYSTYRENE, RELAXATION, SIMULATION, TEMPERATURE, THERMODYNAMICALLY CONSISTENT, TRANSITION, UNIAXIAL
Abstract

The reorientation of dye molecules can be used to monitor the segmental dynamics of a polymer melt. We utilize this technique to measure stress-induced mobility in a lightly cross-linked poly(methyl methacrylate) (PMMA) glass during tensile creep deformation. At 377 K (18 K below the glass transition temperature T(g)), the mobility increased by a factor of 100 during deformation with a stress of 20 MPa. Generally, the mobility increased as the stress, strain, and strain rate increased. After removing the stress, we observed that the enhanced mobility slowly disappeared during strain recovery. At 377 K, when the stress is lower than 11 MPa, almost no mobility enhancement was observed. Once the stress crossed this threshold value, the mobility dramatically increased. (c) American Institute of Physics.

DOI10.1063/1.2868774
Alternate JournalJ. Chem. Phys.