Determination of molar mass distribution of alkyl polyethylene glycol ethers

A process based on gas chromatographic separation and on the computerized evaluation of the results has been developed for the determination of the distribution and distribution coefficients of alkyl polyglycol ethers, formed in the competitive, consecutive reaction of fatty alcohol and ethylene oxide. A comparison of experimental and theoretical distributions showed that the distribution is the Weibull‐Nycander‐Gold type for potassium hydroxide catalyst, and the Flory type in the antimony pentachloride catalyst. The characteristic of the distribution does not change with reaction parameters in either type of distribution, though actual distribution is slightly modified by temperature. In determinations of Weibull‐Nycander‐Gold's c and Natta‐Mantica's ci‐s distribution coefficients, the Weibull‐Törnquist effect, i.e., the changing of the distribution coefficients with ethoxylation, has been experimentally proven in the example of ethoxylation catalyzed with potassium hydroxide.