= Przemyslaw Kubisa
{c}
\b[Przemyslaw Kubisa] studied the use of <ionic liquids> in <polymerization>. His 2004 review examined their solvent role, including effects on polymerization kinetics and separation of polymer from catalyst-containing reaction media.<Application of ionic liquids as solvents for polymerization processes by Przemyslaw Kubisa>[published byline and Abstract]{ref}
The solvent is part of the chemical system rather than merely an inert container. It can alter the environment of an active chain end, the solubility of growing chains and the partition of catalyst and product. Consequently equal monomer conversion in two media does not guarantee equal chain lengths or equal product purity.
An original ideal-chain calculation makes one distinction precise. Suppose $0.100\,\mathrm{mol}$ of monomer is combined with $0.001\,\mathrm{mol}$ of initiator, every initiator forms exactly one growing chain, and there is no chain transfer or termination. At conversion $x=0.80$, the <degree of polymerization> contributed by incorporated monomer is
$$
\overline n=\frac{x n_{M,0}}{n_{I,0}}=80.
$$
If only half the initiator forms chains under the same assumptions, that average becomes 160, despite equal monomer conversion. Conversely, <chain transfer> can increase the chain count and lower the average.
The model is deliberately idealized, not a measurement in Kubisa's review. It shows why solvent comparisons need chain-count and molecular-size information as well as reaction yield. A solvent enabling convenient catalyst recovery still requires separate evidence for its influence on the polymerization mechanism.
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