Distinctive manifestations of segmental motion in amorphous poly(tetrahydrofuran) and polyisobutylene
- Naval Research Lab., Washington, DC (United States)
Polyisobutylene (PIB) and poly(tetrahydrofuran) (PTHF) exhibit segmental relaxation behavior that is distinctly different from that found for other amorphous polymers. These unusual properties include a segmental relaxation dispersion that is much broader when measured mechanically than as seen by other spectroscopic techniques, a relative insensitivity of the segmental relaxation time to temperature, a small steepness index, and an absence of encroachment of the segmental modes in time scale toward the Rouse region as temperature is lowered. It is proposed herein that these phenomena are the result of the very low extent to which segmental relaxation in PIB and PTHF is constrained by nonbonded neighboring segments. This weak intermolecular coupling, deduced from quasi-elastic neutron scattering measurements, solid-state NMR spectroscopy, and the temperature dependence of the segmental relaxation time, arises from the smooth, symmetric, and flexible structure of the two polymers.
- OSTI ID:
- 6540443
- Journal Information:
- Macromolecules; (United States), Vol. 26:11; ISSN 0024-9297
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC POLYMERS
MECHANICAL PROPERTIES
MOLECULAR STRUCTURE
NEUTRONS
NMR SPECTRA
RELAXATION TIME
SCATTERING
TEMPERATURE DEPENDENCE
TETRAHYDROFURAN
BARYONS
ELEMENTARY PARTICLES
FERMIONS
FURANS
HADRONS
HETEROCYCLIC COMPOUNDS
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
POLYMERS
SPECTRA
360603* - Materials- Properties