Living/controlled systems Livingness

In Section 9.4.1 we discussed ideal living polymerization. Let us examine the livingness of the microflow system-controlled cationic polymerization here. 

Therefore, all requirements for living polymerization seem to be satisfied, at least in a practical sense, in the microflow system controlled cationic polymerization. The livingness strongly depends on the reaction time. In a very short period of time highly reactive intermediates, in this case reactive propagating polymer ends, can survive and they can be utilized for subsequent reactions when different monomers or a terminating reagent are added. This concept is quite similar to that discussed in Section 6.3. 

A similar analysis may be applied to this system, but now assuming that the active chains are in equilibrium with a reservoir of dormant chains with Kgq = 10 . Eqn (2.20) shows that now only 1% of the original chains have decomposed in 28 h. However, 95% of the monomer is consumed by these reversibly-deactivated chains in about 100 min. The reversible-deactivation equilibrium has thus transformed a poorly controlled, apparently non-living system into a controlled/living system with practical synthetic possibilities. This analysis also assumes that the ratio ktr,sp/kp was unaffected by whatever system change (solvent, counterion, temperature, etc.) that was carried out to create the large reservoir of dormant chain ends. Very likely, the decrease in ionicity e.g., elimination of free ions in the system) also caused this number to become smaller such that the intrinsic livingness of the system was also improved. 

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