Interfacial tension in polymer blends

摘要

Theoretical models of the interfacial tension coefficient in polymer blends, nu(12), were evaluated. A new working relation was derived that makes it possible to compute nu(12) from the chemical structure of two polymers. The calculations involve determination of the dispersive, polar and hydrogen-bonding parts of the solubility parameter from the tabulated group and bond contributions. The computed values of nu(12) for 46 blends were found to follow the experimental ones with a reasonable scatter of +/- 36%. Next, the experimental methos of nu(12)-measurements were critically examined. Although many have been developed for low viscosity Newtonian fluids, most are irrelevant to industrial polymeric systems. For the present studies two were selected. Values of nu(12) were measured using the so-called "capillary breakup method," and a newly developed method based on the retraction rate of deformed drop. [References: 23]