Аннотация:Changes of gas transport parameters of amorphous glassy
polymer films with various prehistory were analyzed. Films were
subjected to different physical treatments (biaxial stretching,
annealing, removal of residual solvent, physical aging, swelling in
nonsolvents and supercritical CO2, etc.).
In all the cases the diffusion coefficients followed with good
accuracy a well-known equation lnD = a - b•d2, here d is the
kinetic diameter of gas molecules. The parameters a and b are
also sensitive to the treatments of the polymers and, in addition,
linearly correlate with each other.
By combining equations of Eyring and Meares, it was
demonstrated that the parameters a and b can characterize the
deviation from equilibrium state of polymers after particular
treatment. It was shown that changes of cohesive energy and
enthropy of basic state can be calculated.
These parameters were chosen as quantitative characteristics of
chain packing ordering of amorphous polymer. It was shown that
increases in chain packing ordering of the basic state of polymer
matrix induce higher selectivity of diffusion.