Chemistry Reference
In-Depth Information
TABLE 3.2
Molecular-Mass Characteristics of
Cis
-1,4-Polyisoprene 1 and 2 Are the
Methods of Catalyst Preparation
C τ
,
min
Fraction I
Fraction II
Fraction III
M
w
×10
-4
M
w
/M
n
M
w
×10
-4
M
w
/M
n
M
w
×10
-4
M
w
/M
n
1
2
1
2
1
2
1
2
1
2
1
2
3
17.1
2.6
43.2
43.6
4.6
4.8
25.4
21.4
3.7
3.8
20
56.3
4.2
46.5
57.5
4.0
5.9
23.7
22.6
3.4
3.7
C-1
40
64.9
4.6
47.4
62.7
4.1
5.8
27.6
28.9
3.6
3.6
90
72.2
5.1
54.3
61.4
4.3
6.2
26.8
22.4
3.7
3.6
3
24.3
3.3
39.5
54.8
4.3
4.9
21.1
22.3
3.8
3.7
20
69.7
3.8
41.2
67.5
3.9
4.6
24.6
24.6
3.7
3.4
C-2
40
78.4
3.7
42.6
72.8
4.4
4.3
26.3
22.4
3.3
3.5
90
84.6
4.0
58.0
73.2
4.3
4.2
24.7
24.3
3.5
3.3
3
66.2
60.5
3.9
3.8
22.4
20.0
3.8
3.6
20
75.4
71.1
3.7
3.5
28.1
21.3
3.7
3.7
C-3
40
79.6
78.8
4.1
4.0
21.5
23.6
3.8
3.8
90
81.6
79.6
3.9
3.8
23.2
26.8
3.6
3.3
3
81.2
72.7
3.6
3.7
25.4
20.3
3.8
3.6
20
62.7
51.3
3.3
3.2
24.8
21.6
3.7
3.7
C-4
40
57.6
44.3
3.1
3.2
23.2
26.8
3.6
3.6
90
61.4
48.2
3.2
3.4
19.6
21.5
3.1
3.3
The solution of the inverse problem of the formation of the MWD in
the case of cis-1,4-polyisoprene made it possible to obtain curves of the
active site distribution over kinetic heterogeneity (Figs. 3.3-3.6). As a re-
sult of averaging of the positions of all maxima three types of polymeriza-
tion site that produce isoprene macromolecules with different molecular
masses were found:
type A (lnM =10.7), type B (lnM = 11.6), and type C (lnM = 13.4).
