Chemistry Reference
In-Depth Information
FIGURE 5.4
The dependences of limiting draw ratio in ZD l
ZD
on molecular weight of
polymer chain par between nodes of cluster network
M
cl
(1) and macromolecular binary
hooking's network
M
e
(2) for PASF films, prepared from various solvents [21].
There are several methods of limiting draw ratio theoretical estimation
and the authors of Ref. [21] use the two of them. Within the frameworks of
rubber high-elasticity concept the limiting draw ratio l
1
is determined as
follows [25]:
l=
n
1/2
,
(5.7)
1
st
where
n
st
is macromolecule independently mobile kinetic units number be-
tween entanglements nodes.
For polymers the statistical segments is accepted as such kinetic unit
[35]. Then the value
n
st
can be calculated according to the Eq. (2.17).
Donald and Kramer [20] assumed, that the greatest draw ratio l
2
could be determined according to the relationship:
L
d
e
l =
,
(5.8)
2
e
where
L
e
is polymer chain part length between entanglements nodes,
d
e
is distance between entanglements nodes in indeformed polymer. These
