Abstract
A study of several base‐catalyzed propylene oxide—ethylene oxide adducts of glycerin and certain model compounds has shown that an infrared absorption band at 10.30 μ can be associated with a structural entity represented by an oxyethylene unit attached to an oxypropylene unit at the secondary position. Coupled with other information such as total oxyethylene content and primary hydroxyl content, this finding has proved most useful in differentiating average molecular structure for commercial polyether polyols used in the manufacture of polyurethanes.