Purification of Fluorous Polyoxetane Diols by Liquid-Liquid Extraction

Important engineering polymers such as polyurethanes and polyesters use diols as one component during polymerization. Polydiols are also used to incorporate certain function groups into these polymers. Fluorous polydiols, which are essential for our surface science studies, are used for polyurethanes surface modifiers. These polyoxetanes are prepared by ring-opening polymerization, which also produces side products such as cyclics and monofunctional alcohols. The presence of cyclics and monofunctional alcohols can jeopardize surface and mechanical properties. This paper describes a liquid-liquid extraction procedure to purify two important series of fluorous polyoxetanes. The phase behavior of the polyoxetanes in solvent systems was determined in order to optimize the extraction process.