POLYPHOSPHAZENE MEMBRANES: PART 1. ISOPROPANOL/DYE SEPARATIONS

Research has been conducted at the Idaho National Engineering and Environmental Laboratory to determine the characteristics of phosphazene polymers when used as membranes for chemical separations. Phosphazene chemistry allows tailoring of the polymers' mechanical and chemical properties to suit particular applications. Separations discussed in this paper are models for several applications needed in the chemical industry. Ligands on the polymers tested have included modified sugars, various glycols, and substituted phenols. In some cases all of the substituents on the polymer were the same entity. In other cases, up to three different ligands were attached in attempt to develop polymers with all of the needed properties. Physical properties of the different materials varied from film forming rubbers to sticky materials. Some of the polymers gave good fluxes, excellent separations, and lasted for weeks, while others started out with good properties but failed rapidly. A description of the separation performance relative to the separation of isopropanol from dye is given in this paper.