Chemistry Reference
In-Depth Information
a
1,5
1,0
10
0,5
11
0,0
20
- 0,5
11
- 1,0
21
- 1,5
21
- 2,0
0
100
200
300
400
500
600
700
800
r
b
1,6
10
1,4
11
1,2
21
21
1,0
11
0,8
20
0,6
0,4
0,0
0,2
0,4
0,6
0,8
1,0
y
Fig. 14 Breitenbach Wolf plot with respect to the segment number (a) and with respect to the
chemical composition (b). The
numbers
indicate the final fraction number. The
solid lines
are
calculated using the parameter given in (
64
) and the
broken lines
are obtained using the parameters
of (
65
)
large in order to ensure an effective fractionation according to the chemical
composition.
For the production of the intermediate, as for the production of the final fraction,
a temperature gradient must also be established. This gradient can be chosen to be
linear or nonlinear. The nonlinear temperature gradient is selected in such a way
that every final fraction contains the same amount of copolymer segments. The
fractionation results are demonstrated in Fig.
15
, where the distribution functions
with respect to the segment number for the fraction obtained from the third
intermediate fractions are shown. It can be recognized clearly that the second
approach of keeping the amount of polymer in every final fraction constant is the
