Conditions of entropy-enthalpy compensation

Summary of LC Systems under Conditions of Entropy-Enthalpy Compensation... 

All known LC systems under critical and limiting conditions reported over the last 25 years have been summarized. This collection, of over 180 systems, indicates for approximately 37 homopolymers, the most appropriate systems from the point of view separation up to high molar mass and with full recovery. It also enables to reduce the time which would be necessary for identifying the composition of the mobile phase. Suitable alternatives for the separation of different parts of a studied copolymers under conditions of entropy-enthalpy compensation can be identified. Furthermore, the data have been tested from point of view of correlation s between some experimental characteristics of the critical systems. 

The compilation of data confirms that critical conditions are a generally valid phenomenon in LC of polymers. Critical conditions are highly sensitive to very small differences in chemical and structural composition of macromolecules. For this reason LC under conditions of entropy-enthalpy compensation will likely play the increasingly important role in the future of polymer separations including for polyolefins (Fig. 14). 

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