Primary and secondary hydroxyl group content of polypropylene glycols

✍ Scribed by Hanna, J. Gordon ;Siggia, Sidney

• Publisher: John Wiley and Sons
• Year: 1962
• Weight: 426 KB
• Volume: 56
• Category: Article
• ISSN: 0022-3832
• DOI: 10.1002/pol.1962.1205616402

✦ Synopsis

Abstract

When propylene oxide is polymerized or when it is added onto an alcohol or phenol, the terminal hydroxyl groups can be of primary or secondary types, depending on how the epoxide ring opens. The nature of the terminal hydroxyl group becomes important if the polyglycol ether is reacted further, as in the case of polyurethane foams. The primary hydroxyl group reacts much more rapidly with isocyanates than the secondary hydroxyl group, and hence the performance of the polyglycol varies with the ratio of primary to secondary hydroxyl group content. An analytical method has been developed to differentiate the primary from the secondary hydroxyl groups on polypropylene glycol, and a study was made of the variation in the ratios of the two hydroxyl types versus molecular weight of the polyglycol and versus other chemical treatments to which the polyglycol was exposed.