Chemistry Reference
In-Depth Information
30
Single-site (PL1880)
Ziegler-Natta (ATTANE 4203)
Single-site (4.7 mol% Octene whole)
Ziegler-Natta (4.7 mol% Octene whole)
25
"Non Crystallizable
Fraction"
20
15
10
5
0
20
40
60
80
100
TREF Elution Temperature (
°
C)
Figure 4.
Comonomer versus elution temperature relationship for random copolymers.
single-site catalysis (AFFINITY
TM
PL1880,
0.90 g/cm
3
,1I
2
). As shown for these polymers
produced with the same comonomer type, a
distinct relationship between the elution
temperature and comonomer content is
observed, indicating that regardless of the
catalyst nature, the fractions from these
random copolymers, for all practical pur-
poses, have a statistically random distribu-
tion of comonomer. Wild has demonstrated
that the peak elution temperature directly
relates to the degree of short chain
branching in a copolymer.
[6]
Brull et al.
has demonstrated that the melting point or
crystallization point depression of propylene-
alpha olefin copolymers occurs linearly
with increasing comonomer content and
type regardless whether the analysis was
performed in the melt or solution.
[7]
Table 3.
Ziegler-Natta LLDPE TREF fractionation results.
Example - Ziegler-Natta Ethylene-Octene Copolymer
(ATTANE
TM
4203, 0.90 g/cc, 0.8 I2)
Fractionation
Temperature
(
8
C)
Weight
Fraction
Recovered
ATREF T (
8
C) Mol %
Octene
(NMR)
Table 4.
Single-site LLDPE TREF fractionation results.
20
0.08
20
12.0
20-35
0.02
46.5
10.0
35-40
0.050
49
8.0
Example - Single-site Ethylene-Octene Copolymer
(AFFINITY
TM
PL1880, 0.90 g/cc, 1.0 I2)
Fractionation
Temperature
(
8
C)
40-45
0.035
56.5
7.0
45-50
0.047
57.5
6.6
Weight
Fraction
Recovered
ATREF T
(
8
C)
Mol %
Octene
(NMR)
50-55
0.067
61
6.0
55-60
0.079
63.5
5.4
60-65
0.105
67.5
4.9
65-70
0.104
72
4.3
40-45
0.025
56
7.3
70-75
0.110
75.5
3.7
45-50
0.041
61.5
6.5
75-80
0.089
79
3.1
50-55
0.073
63.5
5.7
80-85
0.062
83.5
2.5
55-60
0.124
66.5
5.3
85-90
0.045
90
1.7
60-65
0.180
69.5
4.9
90-95
0.041
95.5
1.1
65-70
0.228
72
4.4
95-100
0.056
100
0.5
70-75
0.241
74
4.2
100-105
0.007
101
0.2
75-80
0.050
76.5
3.8
