Development of and gas permeation study of homo and copolymers from the family of polyphenylene oxides

Abstract

Membrane gas separation emerged as a commercial process on a large scale during the 1980s. When compared to other gas separation processes such as cryogenics, adsorption and absorption, membrane separation competes primarily on the basis of overall economics and convenience, but not on the basis of product purity. For example, membranes have been used for offshore natural gas processing because they reduce the size and the weight of the processing units, require less maintenance and less operator supervision. In order to improve product purity, development of new membrane materials, and modification of existing membrane material for better gas separation properties, is required. This research focused on preparation and characterization of new copolymers from the family of polyphenylene oxides. This family of polymers was chosen because of the properties of its best-known representative, poly(2,6-dimethyl-1,4-phenylene oxide), which shows one of the highest rates of permeability for gases among glassy polymers, exhibits excellent film-forming properties, and is resistant to a number of chemical agents. The study was divided into two parts: (1) homopolymers and both block and random copolymers of different composition were synthesized by oxidative coupling of 2,6-diphenylphenol and 2,6-dimethylphenol; (2) the physical and gas transport properties of the polymers were determined. (Abstract shortened by UMI.)