13C NMR characterization of ethylene oxide/propylene oxide adducts

Analytical studies are essential if ethylene oxide (EO)/propylene oxide (PO) adducts are to be comprehensively characterized. Because hardly any detailed information on their structure has previously been available, studies were carried out to assess the value of the information obtained by 13C NMR spectroscopy. The complex identification of the signals undertaken permitted detailed conclusions to be drawn about the structure of these products. The following structure parameters can be determined: Differentiation between random and block copolymers, persistence ratio (measure of the deviation from a fully random statistics), mean sequence lengths of EO/PO sequences, number of blocks per 100 monomeric units, triad probabilities, and starter and end‐groups.