Carbowax polyethyleneglycol

The polarity of the solute is crucial for the choice of stationary compound, which in an optimal case would have a similar polarity than the solute. Common stationary phases in open tubular columns are cyanopropylphenyl dimethyl polysiloxane, carbowax polyethyleneglycol, biscyanopropyl cyanopropylphenyl polysiloxane and diphenyl dimethyl polysiloxane. For packed columns there are more options available. 

In the case of polyglycols of high molecular weight, some manufacturers attach numbers to their trade names, eg, the Union Carbide Co uses such names as Caibowax 1340, Carbowax 4000 etc for their solid polyethyleneglycols. The Dow Chemical Co calls their products Polyglycol 400, E600, 1200 and E4000... 

A popular series of polar phases is the polyethyleneglycols of this series the Carbowax line is one of those commercially available. The structure of this polymer is... 

Table 2 Retention time (log k) and molecular interaction energy values for a polyethyleneglycol (Carbowax ) phase (CPWAX, DBWAX). Reproduced by permission of Institute for Chromatography, ref. 13.

Carbowax is the trade name of Union Carbide Corp. for their polyethyleneglycols. 

Fig. 4.7. Structure of Carbowax 20M, a polymeric polyethyleneglycol with an average molecular weight of 20,000.

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