Стр. 95 - ДЛЯ ППС

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concentration of the polymer as the concentration of the polymer chains is not
correct. A solution of the polymer chains, that - the two-phase system
consisting, in the simplest case of PS and water. If the concentration of the
polymer chains is large enough, such a mixture is called gel.
Given the above, the effect of the polymer chain on the activity and amount
of water in the PS must be reflected in the curve describing the relationship of
water with polymer concentration in the water vapor pressure above it (the water
sorption isotherm, i.e. polymer). This curve on the one hand should be similar to
the curve for the respective monomer, and on the other should be different from
it, because the polymer solution has a specific minimum concentration at a water
activity equal to unity.
The second option suggests that the polymer chain has an impact on water
quality for all values of
aw.
In this case, the dependence of the polymer must be
related to the dependence of the monomer for a certain coefficient, which, inter
alia, give a specific value of
nw
at
aw,
unity. It is known in practice the second
embodiment is realized.
Water sorption isotherm of the polymer, dependence of its activity on the
concentration of the monomer solution can be defined by the equation to give
the same species with the same set of coefficients, (3 and y given polymer chain
influence the experiment).
To check compliance with the theoretical isotherms calculated according to
the equation, the experimental isotherms of sorption and desorption of water, a
series of experiments isopiestic method [16] and the method of dynamic
desorption porosimetry (DCF) [15, 17]. These methods at atmospheric pressure
and a temperature of 298 K obtained sorption isotherms (desorption) of water for
a number of polymers.
Calculation and construction of theoretical isotherms of water sorption for
different values of Kd values conducted on the basis of published data on the
dependence of the amount of water from its activity in the solutions of the
corresponding monomers. For polyvinyl alcohol (PVA) as the monomeric
analogue is chosen ethanol, to strongly acidic cation exchangers based on
styrene crosslinked with divinylbenzene (DVB) - ethyl benzenesulfonic acid and
its salts, in chloride form strong base anion exchangers on the same basis
(styrene-divinylbenzene) - tetramethylammonium chloride.
In a first step swelling investigated in a steam atmosphere of crosslinked
PVA. The crosslinked PVA PVA obtained by crosslinking linear
epichlorohydrin as described in [18]. On it two polymers were prepared: PVA
-PVA and 10-20 (10 and 20 mass% of epichlorohydrin in the mixture in
crosslinking.).
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