Chemistry Reference
In-Depth Information
Table 3.13.
Phase property of polymers
3
.
61
and monomers
R
Monomer
Polymer
CH
3
O
−
K63(N23)I
g38N62I
C
2
H
5
O
−
K92I
g34N82I
n-C
3
H
7
O
−
K71(N26)I
g26N58I
n-C
4
H
9
O
−
K69(N41)I
g19N67I
n-C
5
H
11
O
−
K52(N29)I
g10N51I
n-C
6
H
13
O
−
K49(N45)I
g5N60I
n-C
7
H
15
O
−
K46(N36)I
g1N48I
n-C
8
H
17
O
−
K54(N48)I
g-2N61I
n-C
3
H
7
K 38 (N -20) I
g 12 I
Table 3.14.
Molecular weights and
Tg
of PE-R as well as phase transition property
of monomers.
PE-R
R
Mn
(
Mw
(
Mw
/
Mn Tg
∗
(
◦
C)
Property of monomers
(in
◦
C)
×
10
−
4
)
×
10
−
4
)
PE-H
H
5.4
10
1.9
170
K 88 N 95 I
PE-OC
1
OCH
3
13
30
2.3
160
K 184 N 195 I
PE-OC
2
OC
2
H
5
4.5
9.5
2.1
130
K 150 N 168 I
PE-OC
4
OC
4
H
9
24
88
3.7
80
K 109 S 130 N 167 I
∗∗
∗∗
∗∗
PE-CN
CN
200
K 216 N 257 I
PE-C
1
CH
3
7.7
22
2.9
172
K 123 N 128 I
K 106 ( N 102 ) I
∗∗∗
PE-C
2
C
2
H
5
6.8
17
2.5
160
PE-C
4
C
4
H
9
2.8
8.6
3.0
130
K 44 S 98 I
∗
Above
Tg
, all the polymers have a nematic phase which is thermally very stable;
∗∗
It is not soluble in THF, intrinsic viscosity was given as 1.1 g/dl in DMF;
∗∗∗
Monotropic.
that the molecules are parallel aligned and the distance between any two
vinyl carbons of two neighboring molecules is small.
All the
polymers are non-crystalline as revealed by X-ray anal-
ysis. There is only a very diffuse halo at 20 degrees and a diffuse peak
at 5.5 degrees for two corresponding respectively to the lateral pack-
ing of the chains and to the length of the side groups (16 A, calculated
from
d
=
λ/
2sin
θ
). The glass transition temperatures are also shown in
Table 3.14. At temperatures above
Tg
, the polymers all have a nematic
phase. These mesophases are very stable and no isotropization tempera-
ture has ever been observed before decomposition starts to occur at about
PE-R
