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The Free Volume and Its Recovery in Pressure‐Densified and CO 2 ‐Swollen Heterocyclic‐Ring‐Containing Fluoropolymers
Author(s) -
Dlubek Günter,
Pionteck Jürgen,
Yu Yang,
Thränert Stefan,
Elsayed Mohamed,
Badawi Emad,
KrauseRehberg Reinhard
Publication year - 2008
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200800189
Subject(s) - volume (thermodynamics) , swelling , polymer , polymer chemistry , thermodynamics , chemistry , materials science , equation of state , composite material , ring (chemistry) , analytical chemistry (journal) , organic chemistry , physics
Changes in the free volume in CYTOP due to pressure densification and swelling with CO 2 have been examined using PALS and PVT experiments. Employing the Simha‐Somcynsky equation of state the specific hole free, V f , and occupied, V occ , volumes were estimated. The change in the total volume due to the pre‐treatments occurs exclusively in the hole free volume and the relative change in V f is one order of magnitude larger than in the total volume. V occ shows no memory for the history of the polymer glass. The mean and width of the size distribution of subnanometre holes in the glassy state decrease upon densification and increase upon swelling. The volume changes which are frozen in the polymer glass begin to recover at temperatures distinctly below T g .