Showing papers by "Yoshiyuki Okamoto published in 2016"

New amorphous perfluoro polymers: perfluorodioxolane polymers for use as plastic optical fibers and gas separation membranes

Abstract: To address the need for perfluoro polymers with higher Tg, we have prepared and characterized various perfluorodioxolane monomers via direct fluorination of the hydrocarbon precursors. These monomers were readily polymerized in bulk or in solution initiated by perfluorodibenzoyl peroxide. The polymers obtained have relatively high Tg(~160°C) and exhibited low material dispersion. These polymers are completely amorphous and soluble in fluorinated solvents. The polymers are also chemically and thermally stable (Tg > 300°C). Thus, these perfluorodioxolane polymers may be used as plastic optical fiber material where high Tg is required, such as in automobile and aircraft application. These perfluorodioxolane polymers were also investigated for use as gas separation membrane. Among these polymers, the copolymer of perfluoro (2-methylene-1,3-dioxolane) and perfluoro (2-methylene-4,5-dimethyl dioxolane) showed superior gas separation performance compared with the commercial perfluoro polymers for a number of gas pair, including CO2/CH4, He/CH4, H2/CH4, and N2/CH4. Copyright © 2015 John Wiley & Sons, Ltd.

Gas separation membranes based on fluorinated and perfluorinated polymers

Abstract: A process for separating components of a gas mixture using gas-separation copolymer membranes. These membranes use a selective layer made from copolymers of partially fluorinated or perfluorinated dioxolane monomers and a second monomer, such as dioxane or a partially fluorinated dioxolane. The resulting membranes have superior selectivity performance for gas pairs of interest while maintaining fast gas permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon® AF, Hyflon® AD, and Cytop®.