Chemistry Reference
In-Depth Information
The nanofiller and interfacial regions total fraction jif)
n
+ j
if
) was esti-
mated with the help of the formula [9]:
E
E
(
)
1,7
n
=+ +
1
11
φφ
,
(11.5)
n
if
m
where
E
n
and
E
m
are elasticity moduli of nanocomposite and matrix polymer,
respectively.
The conditional sign and composition of the considered polymeric mate-
rials are adduced i
n
Table 11.1
.
Then, having determining structure pliable
regions fraction or j
l.m.
(the devitrificated loosely packed matrix elasticity
modulus is approximately by three orders of magnitude smaller than the
corresponding characteristic for the remaining structural components [12]),
the curves e(
t
) can be described in the case of creep testing with the help of
the Eq. (11.1). The value e is given in relative units in such a way as that
proportionality coefficient in the indicated relationship will be equal to one.
from the plots of Fig. 11.1, the Eq. (11.1) describes well the creep experi-
mental curves e(t) for both initial HDPE and nanocomposites on its basis.
Let us note the principal distinction of approaches, applied by the authors of
Ref. [3, 4] in the present work as well. In the last case very simple Eq. (11.1)
was used, in which e is a function of the structure state only. At the same
time in Refs. [3, 4] for e description within the frameworks of Maxwell,
Kelvin, Burgers models and so on a large number of parameters was used,
which are polymeric material property, but not its structural characteristics.
In other words, in Ref. [7] the relation property-structure is obtained, that is
the main distinction of the offered method from those used ones earlier [3,
4].
Thus, the structural model for polyethylene and nanocomposites on its
basis creep process description is offered, taking into account the indicated
polymeric materials structure heterogeneity. This treatment is given within
the frameworks of the cluster model of polymers amorphous state structure
and shown the good correspondence wit experiment [7].
