Amphiphilic Polyalkylene Oxides

4 ANALYSIS OF ALKYLENE OXIDE-BASED POLYMERS 17.4.1 Amphiphilic Polyalkylene Oxides 

Fatty alcohol and fatty acid ethoxylates are amphiphilic compounds that are commonly used as nonionic surfactants and emulsifiers in many applications, such as cosmetic and care products and in textile fabrication. They serve as antistatic lubricants and viscosity regulators. 

FIGURE 17.5 Reaction scheme for the synthesis of alkyl(aryl) ethoxylates. 

FIGURE 17.6 Chromatogram of a technical octylphenoxy PEO sample separated by LCCC, stationary phase RP-18, mobile phase methanol-water 86 14% by volume (reprinted from Adrian et al., 1998, with permission of Advanstar Communications, UK). 

As a typical application, the separation of an octylphenoxy-terminated PEO with respect to the terminal groups by LCCC is presented in Fig. 17.6. Similar to previous investigations on RP-18 stationary phases (Gorshkov et al., 1990 Pasch and Zammert, 1994), the critical eluent composition was achieved with methanol-water 86 14% by volume. Five well-separated peaks appeared in the chromatogram, which could be identified by MALDI-TOF mass spectrometry as being different functionality fractions. Accordingly, separation took place strictly with respect to the chemical structure of the end groups. 

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