The Spin Probe Dynamics and the Free Volume in a Series of Amorphous Polymer Glass-Formers

2011 ◽  
Vol 305 (1) ◽  
pp. 108-115 ◽  
Author(s):  
H. Švajdlenková ◽  
M. Iskrová ◽  
O. Šauša ◽  
G. Dlubek ◽  
J. Krištiak ◽  
...  
Keyword(s):  
Free Volume ◽  
Spin Probe ◽  
Amorphous Polymer ◽  
Polymer Glass

scholarly journals On the Mutual Relationships between Molecular Probe Mobility and Free Volume and Polymer Dynamics in Organic Glass Formers: cis-1,4-poly(isoprene)

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 294
Author(s):  
Helena Švajdlenková ◽  
Ondrej Šauša ◽  
Sergey V. Adichtchev ◽  
Nikolay V. Surovtsev ◽  
Vladimir N. Novikov ◽  
...  
Keyword(s):  
Free Volume ◽  
Spin Probe ◽  
Hyperfine Coupling Constant ◽  
Organic Glass ◽  
Molecular Probe ◽  
Positron Annihilation Lifetime ◽  
Broadband Dielectric Spectroscopy ◽  
Relaxation Modes ◽  
Reorientation Dynamics ◽  
In Cis

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.

scholarly journals On the free-volume model of multi-shape memory effect in amorphous polymer

2019 ◽  
Vol 28 (12) ◽  
pp. 125012
Author(s):  
Xiaodong Wang ◽  
Yuheng Liu ◽  
Haibao Lu ◽  
Yong-Qing Fu
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Free Volume ◽  
Memory Effect ◽  
Amorphous Polymer ◽  
Volume Model ◽  
Free Volume Model

Free Volume and Finite-Size Effects in a Polymer Glass under Stress

2007 ◽  
Vol 99 (21) ◽  
Author(s):  
Robert A. Riggleman ◽  
Hau-Nan Lee ◽  
M. D. Ediger ◽  
Juan J. de Pablo
Keyword(s):  
Free Volume ◽  
Size Effects ◽  
Finite Size ◽  
Finite Size Effects ◽  
Polymer Glass

Spin probe dynamics in relation to free volume in crystalline organics from ESR and PALS: Cyclohexane

2016 ◽  
Vol 643 ◽  
pp. 98-102 ◽  
Author(s):  
H. Švajdlenková ◽  
B. Zgardzinska ◽  
M. Lukešová ◽  
J. Bartoš
Keyword(s):  
Free Volume ◽  
Spin Probe

Free Volume and Density Gradients of Amorphous Polymer Surfaces As Determined by Use of a Pulsed Low-Energy Positron Lifetime Beam and PVT Data

2004 ◽  
Vol 37 (11) ◽  
pp. 4201-4210 ◽  
Author(s):  
John Algers ◽  
Ryoichi Suzuki ◽  
Toshiyuki Ohdaira ◽  
Frans H. J. Maurer
Keyword(s):  
Free Volume ◽  
Positron Lifetime ◽  
Amorphous Polymer ◽  
Low Energy ◽  
Polymer Surfaces ◽  
Density Gradients ◽  
Pvt Data

A Model for Mechanically Induced Densification of Glassy Polymers

1999 ◽  
Vol 66 (3) ◽  
pp. 702-708 ◽  
Author(s):  
A. D. Drozdov
Keyword(s):  
Composite Material ◽  
Free Volume ◽  
Constitutive Equations ◽  
Specific Volume ◽  
Amorphous Polymer ◽  
Glassy Polymers ◽  
Viscoelastic Response ◽  
Stress Strain ◽  
Small Strains ◽  
Temporary Network

Constitutive equations are derived for the isothermal viscoelastic response of glassy polymers at small strains. An amorphous polymer is modeled as a composite material consisting of a temporary network of long chains, immobile voids, and free volume gas diffusing through the network. The model is applied to analyze stress-induced densification of polymers in tensile and compressive relaxation tests. It is demonstrated that the stress-strain relations adequately predict a decrease in the specific volume observed in uniaxial experiments on polycarbonate.

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