Liquid chromatography under critical

Macko, T. endHunkeler, D. Liquid Chromatography under Critical and Limiting Conditions A Survey of Experimental Systems for Synthetic Polymers. Vol. 163, pp. 61-136. 

Liquid Chromatography under Critical Conditions of Enthalpic Interactions.478... 

The principle of the liquid chromatography under critical conditions (LC CC) was elucidated in Section 16.3.3. The mutual compensation of the exclusion—entropy and the interaction—enthalpy-based retention of macromolecules can be attained when applying in the controlled way the interactions that lead to either adsorption or enthalpic partition. The resulting methods are called LC at the critical adsorption point (LC CAP) or LC at the critical partition point (LC CPP), respectively. The term LC at the point of exclusion-adsorption transition (LC PEAT) was also proposed for the procedures employing compensation of exclusion and adsorption [161]. It is anticipated that also other kinds of enthalpic interactions, for example the ion interactions between column packing and macromolecules can be utilized for the exclusion-interaction compensation. 

The applicability of LC LC to the (ultra) high-molar-mass polymers. Contrary to liquid chromatography under critical conditions, LC LC likely exhibits no upper limit of the sample molar mass [234]. On the other hand, if the difference in elution rates of the barrier forming small molecules and the oligomeric species is too small, the LC LC separation becomes insufficient. As a result, LC CC and LC LC may be considered mutually complementary from the point of view of their applicability in the... 

All above homopolymers are used also for the identification of suitable conditions for the coupled polymer HPLC techniques. Typical examples are liquid chromatography under critical (LC CC) and limiting (LC LC) conditions, and eluent gradient liquid chromatography (EG LC). For the development of latter methods, several defined statistical and block copolymers are available. 

D. Berek, Mater. Res. Innovat. 4, 365, 2001 Round Table Discussion Characterization of block copolymer with liquid chromatography under critical conditions of enthalpic interactions, in International Conference on Coupled, Hyphenated and Multidimensional Liquid Chromatographic Procedures for Separation of Macromolecules, Bratislava, Slovakia, 2001. 

LCCC Liquid chromatography under critical conditions... 

A few years later, by using the same experimental procedures, the same scientists prepared cyclic polybutadienes170 (Scheme 82). THF was the polymerization solvent, which results in a 60% 1,2-content. From the g values was concluded that some of the cyclic polybutadienes (PBd) were contamined by their linear precursors. A high-resolution column set was used in order to separate the linear from the cyclic polymer. In this work the characterization analysis was the most comprehensive presented so far. Recently, these cyclic PSs were analyzed by high-pressure liquid chromatography under critical conditions, which is a method that can separate linear and cyclic macromolecules according to their archi-... 

Figure 12.5 Comparison of size exclusion chromatography (SEC) and liquid chromatography under critical conditions (LCCC) for the bulk enzymatic polymerization of caprolactone in the presence of bifunctional initiator 3 as a function of time. LCCC shows...

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