Handbook of Size Exclusion Chromatography and Related ...

Figure 6shows the results of acontinuous reactor experiment in which the
concentration of initiator in the monomer feed was varied, as shown, while
the monomer feed concentration and r were kept constant. As the initiator
concentrationincreases,theamountofconversionincreasesaccordingtoEq.(13).
Similarly, Eq. (14) predicts that Mw will decrease as initiator concentration
increases, which is also seen in Fig. 6. The exponential approaches to the steady
state are seen between the increments in initiator concentration.
The inset to Fig. 6shows the extrapolation of Mw to f¼0. In the QSSA
Mw(f ¼0) should be proportional to the inverse square root of the initial initiator
concentration, aprediction born out in the inset. Combining the Mw and f data
allows for the determination of k 2 p =kt from a single experiment, such as in
Fig. 6. The value is 11.7L/M s.
Figure 7shows the effect of fluctuating conditions on f and Mw. In the first
part an uninterrupted steady state is obtained. Then, deliberate temperature
Figure 6 Mw and f from ACOMP of a continuous reactor, where the feed reservoir ratio
of initiator to monomer increased after the steady state for each condition was reached. The
inset shows the expected inverse square root dependence on initiator of Mw ( f ¼ 0). (From
Ref. 34.)
© 2004 by Marcel Dekker, Inc.