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compositions PVSZ + Adros characterized by the formation of aggregates of
particles aerosil with aderrbirovaiym LAN layer, these particles form secondary
aggregates and mesh structure.
The kinetics of establishing equilibrium sorption and corresponds
Fikovskomu pseudonormal types. We calculate the effective diffusion
coefficient (D) and built their concentration dependence. The results were
compared with the NMR data and optical interferometry. It is shown that the
anomalously high values of D in the low-Humidity, are associated with excess
free volume of sorbents.
For all investigated in PVP and PVC samples obtained sorption isotherm,
and they have the form of concave and S-OopirsHbix curves. Experimentally
shown that morphological changes in characteristics of sorbent (powder or film),
the degree of dispersion and polymer molecular weight have little effect on its
sorption properties. Grid chemical bonds of the polymer reduces the sorption
capacity. Significant influence prehistory sorbent. Thus, thermal annealing of
films formed from solutions at temperatures near the glass transition
temperature, reduces the sorption capacity of more than twice in the entire range
p/p5.
The expansion of the experimental isotherms on the Langmuir fashion and
Flory-Huggins under the dual sorption model allowed us to obtain the
characteristics of a non-equilibrium state of the polymer sorbent, as well as to
calculate the pair interaction parameters (%) in the polymer systems - water. It
was found that the isotherm may differ significantly according to the Langmuir
component, whereas fashion Flory-Huggins changes slightly. % values obtained
for the PVP can be grouped into two groups: 0.50 % = 0.56 and = 0.75 % - 0.82.
Smaller values of the parameter pair close to independent estimates by other
methods (; /-0.4), larger values have characteristic of crosslinked PVP.
It was shown that regardless of the physical state of equilibrium in the
solution of PVP and PVK (glassy or rubbery). Thermodynamics of interaction
with water is described the concept of a single polymer solutions Flory-Huggins.
This is not contrary to any notion of hydration numbers, nor about the clustering
of water molecules under the influence of the active centers of the PVA polymer
+ water. In contrast to the polymers discussed above, PVA-sorbent is partially
crystalline. It is shown that the sorption localized in the amorphous portion of
the polymer which goes under humidity change from the glassy to the rubbery
state. The nature of the kinetic curves of sorption and concentration dependence
of the diffusion coefficient similar to PVP and PVC. Sorption isotherms are also
two types of concave and B-shaped curves. On sorption properties of PVA
affects the degree of hydrolysis and the molecular weight, in contrast, has little
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