Chemistry Reference
In-Depth Information
where
G
is shear modulus, which can be calculated according to the Eq.
(4.58),
b
is Burgers vector, estimated according to the Eq. (4.7),
l
o
is polymer
main chain skeletal bond length (for PASF
l
o
= 1.25 Å [15]),
C
¢
is character-
istic ratio, which can be calculated according to the Eq. (4.40).
The value s
Y
in the case of ZD defines polymer drawing beginning, that
is, local plasticity zone formation beginning. Therefore, in practice this
stress can be assumed as polymer capacity for work upper boundary [1].
In Fig. 13.6, the comparison of experimental and calculated according
to the Eq. (13.5) PASF yield stress values is adduced, which shows good
enough these parameters conformity.
In its turn, within the frameworks of elastic fracture linear mechanics the
value d
c
is determined as follows [16]:
G
d
=
Ic
.
(13.6)
c
s
Y
FIGURE 13.6
The relation between experimental s
Y
and calculated according to the Eq.
(13.5)
s
draw stress values for PASF film samples [1].
The Eqs. (1.9), (2.20) and (13.6) allow to obtain the following relation-
ship for the value d
c
estimation [10]:
T
2
Gd
Eb l C
p
d
=
Ic
f
,
(13.7)
(
)
c
3/2
∞
0
cl
which is the Eq. (5.1) analog.
