Photochromic and fluorescent probe studies in glassy polymer matrices. 3. Effects of physical aging and molar weight on the size distribution of local free volume in polystyrene

1988 ◽  
Vol 21 (12) ◽  
pp. 3490-3497 ◽  
Author(s):  
John G. Victor ◽  
John M. Torkelson
Keyword(s):  
Size Distribution ◽  
Fluorescent Probe ◽  
Free Volume ◽  
Physical Aging ◽  
Glassy Polymer ◽  
Polymer Matrices ◽  
Molar Weight

scholarly journals Network Topology of the States Probed by a Glassy Polymer during Physical Aging

2019 ◽  
Vol 28 (6) ◽  
pp. 1900036
Author(s):  
Georgios Grigorios Vogiatzis ◽  
Lambèrt Cécile Angelo van Breemen ◽  
Markus Hütter
Keyword(s):  
Network Topology ◽  
Physical Aging ◽  
Glassy Polymer

Free volume and physical aging of poly(vinyl acetate) studied by positron annihilation

1989 ◽  
Vol 22 (5) ◽  
pp. 2302-2306 ◽  
Author(s):  
Y. Kobayashi ◽  
W. Zheng ◽  
E. F. Meyer ◽  
J. D. McGervey ◽  
A. M. Jamieson ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Vinyl Acetate ◽  
Free Volume ◽  
Physical Aging

A Wavelength-Shifting Fluorescent Probe for Investigating Physical Aging

2006 ◽  
Vol 39 (1) ◽  
pp. 224-231 ◽  
Author(s):  
Otto van den Berg ◽  
Wolter F. Jager ◽  
Daniele Cangialosi ◽  
Jan van Turnhout ◽  
Peter J. T. Verheijen ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Physical Aging

scholarly journals A Coupled Thermodynamic Model for Transport Properties of Thin Films during Physical Aging

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 387 ◽  
Author(s):  
Hongjiu Hu ◽  
Xiaoming Fan ◽  
Yaolong He
Keyword(s):  
Thin Films ◽  
Transport Properties ◽  
Free Volume ◽  
Physical Aging ◽  
Field Equations ◽  
Lattice Contraction ◽  
Strongly Coupled ◽  
Coupled Diffusion ◽  
Coupled Field Equations ◽  
Short Time

A coupled diffusion model based on continuum thermodynamics is developed to quantitatively describe the transport properties of glassy thin films during physical aging. The coupled field equations are then embodied and applied to simulate the transport behaviors of O2 and CO2 within aging polymeric membranes to validate the model and demonstrate the coupling phenomenon, respectively. It is found that due to the introduction of the concentration gradient, the proposed direct calculating method on permeability can produce relatively better consistency with the experimental results for various film thicknesses. In addition, by assuming that the free volume induced by lattice contraction is renewed upon CO2 exposure, the experimental permeability of O2 within Matrimid® thin film after short-time exposure to CO2 is well reproduced in this work. Remarkably, with the help of the validated straightforward permeability calculation method and free volume recovery mechanism, the permeability behavior of CO2 is also well elucidated, with the results implying that the transport process of CO2 and the variation of free volume are strongly coupled.

On the Limits of Sensitivity of PALS to Incorporated Free Volume Holes in Polymeric Membranes and Sorbents: Effect of sc-CO2 in Polyhexafluoropropylene

2017 ◽  
Vol 373 ◽  
pp. 261-264 ◽  
Author(s):  
Victor Shantarovich ◽  
Valentin Bekeshev ◽  
Nikolai Belov ◽  
Irina Kevdina ◽  
Mikhail Filimonov ◽  
...  
Keyword(s):  
Low Temperature ◽  
Size Distribution ◽  
Positron Annihilation ◽  
Free Volume ◽  
Polymeric Membranes ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Membrane Materials ◽  
Positron Annihilation Lifetime

Positron annihilation lifetime spectroscopy (PALS) is a recognized instrument for the studies of size-distribution of nanopores (intrinsic free volume holes FVH) in polymers, particularly membrane materials. The limits of this application in the case of “alien” pores, produced by swelling of poly (hexafluoro propylene) PHFP in the gas (CO2) in super-critical (sc-) state are discussed. The obtained conclusions are controlled by measurements of low temperature gas (N2) sorption (LTGS) and by comparison of the data with the results on permeation of various gases through the PHFP membrane. Attention is payed to relaxation with time of the newly created FVH in the PHFP membrane.

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