[70–72]. The total polymer concentration is measured by the intensity of the CH 2
band, whereas the presence of CH 3 groups indicates branching and is characteristic
of PP units. The chain branching in PE may also result in the band at 1,378 cm
À1 ;
therefore, the validity of using the ratio of 1,378 cm
À1 /1,462 cm
À1 was
investigated. This was achieved by constructing the ethylene profile across the
molar mass curve. The ratio of the areas of the bands at 720 cm
À1 and 1,163 cm
À1
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
30
35
40
45
50
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
1
2
3
4
5
6
7
8
9
10
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0
1
2
3
4
5
6
7
8
9
10
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0
1
2
3
4
5
6
7
8
9
10
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0
1
2
3
4
5
6
7
8
9
10
Intensity (2800-3200cm
-1
)
Elution volume (ml)
60ºC Gram-Schmidt
730cm
-1
/720cm
-1
60ºC Gram-Schmidt
998cm
-1 /972cm
-1
Elution volume (ml)
Intensity (2800-3200cm
-1
)
80ºC Gram-Schmidt
998cm
-1
/972cm
-1
Intensity (2800-3200cm
-1
)
Elution volume (ml)
80ºC Gram-Schmidt
730cm
-1 /720cm
-1
Intensity (2800-3200cm
-1
)
Elution volume (ml)
90ºC Gram-Schmidt
998cm
-1
/972cm
-1
Intensity (2800-3200cm
-1
)
Elution volume (ml)
90ºC Gram-Schmidt
730cm
-1
/720cm
-1
Intensity (2800-3200cm
-1
)
Elution volume (ml)
100ºC Gram-Schmidt
998cm
-1
/972cm
-1
A(730cm -1
)/A(720cm -1
)
A(730cm -1
)/A(720cm -1
)
A(730cm -1
)/A(720cm -1
)
A(730cm -1
)/A(720cm -1
)
A(998cm -1
)/A(972cm -1
)
A(998cm -1
)/A(972cm -1
)
A(998cm -1
)/A(972cm -1
)
A(998cm -1
)/A(972cm -1
)
Intensity (2800-3200cm
-1
)
Elution volume (ml)
100ºC Gram-Schmidt
730cm
-1
/720cm
-1
Intensity (2800-3200cm
-1
)
Elution volume (ml)
Fig. 2.16 SEC-FTIR analysis of the ethylene and propylene crystallinity distributions within the
60
C, 80
C, 90
C and 100
C TREF fractions of IPC (reprinted from [37] with permission of
Wiley-VCH)
2.1 Temperature Rising Elution Fractionation
33