Some solution properties of polyoxymethylenes

Perfluoroacetone hydrate (PFAH) is a useful nondegrading solvent for high molecular weight polyoxymethylenes (POM) at ordinary temperatures. Infrared spectroscopic measurements on mixtures of low molecular weight POM diisopropyl ethers and PFAH in carbon tetrachloride solution give evidence of specific polymer—solvent interactions involving hydrogen bonds. Although the viscosity behavior of POM in PFAH and PFAH—H2O mixtures conforms to the Huggins equation, the values of the Huggins constant are not consistent with the values expected on theoretical grounds. Much more satisfactory values are obtained by application of the Schulz—Blaschke viscosity relationship.