Chemistry Reference
In-Depth Information
FIGURE 1.1
The dependence of clusters relative fraction j
cl
on absolute value of specific
Gibbs function of nonequilibrium phase transition |
D
| for amorphous glassy polymers -
im
polycarbonate (1) and polyarylate (2) [3].
Polymeric medium's structure fractality within the indicated above scale
limits assumes the dependence of their density ρ on dimensional parameter
dd
-
,
r
~
L
(1.2)
f
where
d
is dimension of Euclidean space, into which a fractal is introduced.
ed. As one can see, within the limits of the indicated above dimensional
periodicity scales Fig. 1.2 and 1.3 correspond each other, that is, the cluster
model assumes ρ reduction as far as possible from the cluster center. Let us
note that well-known Flory “felt” model [20] does not satisfy this criterion,
since for it ρ ≈ const. Since, as it was noted above, polymeric mediums struc-
ture fractality was confirmed experimentally repeatedly [14-16], then it is
obvious, that cluster model reflects real solid-phase polymers structure quite
plausibly, whereas “felt” model is far from reality. It is also obvious, that
opposite intercommunication is true - for density ρ finite values change of
the latter within the definite limits means obligatory availability of structure
periodicity.