ABSTRACT Friesen 9322727 This Small Business Innovation Research Phase II project will develop novel copolymers with an improved combination of high permeability and high selectivity for use in making membranes for gas and vapor separations. Typically, membranes with high permeabilities have low selectivities, and vice versa. During Phase I, the feasibility of preparing copolymers with an improved combination of permeability and selectivity was successfully demonstrated. The novel substituted polyacetylene copolymers developed in Phase I displayed the physical characteristics necessary for making membranes and were prepared in high (>70%) yield. During Phase II, research will focus on continuing to develop and evaluate copolymers based on monomers use in Phase I; synthesizing and evaluating copolymers made from additional monomers; evaluating the copolymers for industrially important separations; developing procedures for making asymmetric hollow-fiber membranes from the copolymers; and making and testing small hollow-fiber modules. The widespread use of membrane systems for many separations has been limited by the performance of current membranes. Potential commercial applications for high-permeability, high-selectivity membranes include the production of nitrogen from air; the production of oxygen for medical applications; the removal of carbon dioxide from natural gas; the recovery of hydrogen from petroleum-refining process streams; and the separation of volatile organic vapors (e.g., propane/propylene). Keywords: membrane, gas separation, polymer, high permeability, high selectivity p:sbiryhashimiabstracts9322727a.doc