Tucker Woock

Date of Award

January 2016

Document Type


Degree Name

Master of Science (MS)


Chemical Engineering

First Advisor

Ali S. Alshami


Membrane separation is an excellent potential method for purification of natural gas. Multiple polymers have been studied for use in natural gas separation, and two stand above the rest: polyimide and polybenzoxazole. It was found that the selection of monomer precursors could influence the separation properties and resistances of the resultant polyimide and polybenzoxazole membranes. Polybenzoxazole has even better separation properties than polyimide due to the size and distribution of its free volume elements. Methods to influence these properties are similar to those used with polyimides. The intent of this thesis was to compare different dianhydride precursors. My research attempted to compare the permeabilities and selectivities of polybenzoxazole membranes thermally rearranged from hydroxyl-polyimides formed from four dianhydride precursors. The hydroxyl-polyimides were formed by the azeotropic synthesis method, cast into membranes, thermally rearranged into polybenzoxazoles, and underwent permeation testing using a manifold constructed in-house. It was found that hydroxyl-polyimides were indeed formed, but not completely thermally rearranged, and the setup for permeation testing was insufficient to fulfill the goal of this thesis. Thus no conclusions on the effect of the dianhydride bridging group could be made.