On the Mutual Relationships between Molecular Probe Mobility and Free Volume and Polymer Dynamics in Organic Glass Formers: cis-1,4-poly(isoprene)
Open Access
- 18 January 2021
- Vol. 13 (2), 294
- https://doi.org/10.3390/polym13020294
Abstract
We report on the reorientation dynamics of small spin probe 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) in cis-1,4-poly(isoprene) (cis-1,4-PIP10k) from electron spin resonance (ESR) and the free volume of cis-1,4-PIP10k from positron annihilation lifetime spectroscopy (PALS) in relation to the high-frequency relaxations of cis-1,4-PIP10k using light scattering (LS) as well as to the slow and fast processes from broadband dielectric spectroscopy (BDS) and neutron scattering (NS). The hyperfine coupling constant, 2Azz′(T), and the correlation times, τc(T), of cis-1,4-PIP10k/TEMPO system as a function of temperature exhibit several regions of the distinct spin probe TEMPO dynamics over a wide temperature range from 100 K up to 350 K. The characteristic ESR temperatures of changes in the spin probe dynamics in cis-1,4-PIP10k/TEMPO system are closely related to the characteristic PALS ones reflecting changes in the free volume expansion from PALS measurement. Finally, the time scales of the slow and fast dynamics of TEMPO in cis-1,4-PIP10k are compared with all of the six known slow and fast relaxation modes from BDS, LS and NS techniques with the aim to discuss the controlling factors of the spin probe reorientation mobility in polymer, oligomer and small molecular organic glass-formers.Funding Information
- Vedecká Grantová Agentúra MŠVVaŠ SR a SAV (No. 2/0005/20, 2/0157/17)
- Agentúra na Podporu Výskumu a Vývoja (APVV-16-0369)
This publication has 62 references indexed in Scilit:
- Glass Transition Thermodynamics and KineticsAnnual Review of Condensed Matter Physics, 2013
- Field-cycling NMR relaxometry of viscous liquids and polymersProgress in Nuclear Magnetic Resonance Spectroscopy, 2012
- Transport properties of glass-forming liquids suggest that dynamic crossover temperature is as important as the glass transition temperatureProceedings of the National Academy of Sciences of the United States of America, 2010
- Evolution of the Dynamics in 1,4-Polyisoprene from a Nearly Constant Loss to a Johari−Goldstein β-Relaxation to the α-RelaxationMacromolecules, 2004
- Free-volume microstructure of glycerol and its supercooled liquid-state dynamicsJournal of Physics: Condensed Matter, 2001
- X-ray scattering study and molecular simulation of glass forming liquids: Propylene carbonate and salolThe Journal of Chemical Physics, 2000
- Light-scattering spectra of fast relaxation in glassesPhysical Review B, 1998
- Structural Changes near the Glass Transition–Neutron Diffraction on a Simple PolymerEurophysics Letters, 1989
- Power-law behavior in the viscosity of supercooled liquidsPhysical Review B, 1986
- Spin‐probe studies. II. Applications to polymer characterizationJournal of Polymer Science Part A-1: Polymer Chemistry, 1969