Novel polyoxadiazoles with non-coplanar ortho-linked structures as highly CO₂ permselective membranes

Abstract

A novel class of polyoxadiazole membranes containing non-coplanar 1,1′-thiobis(2-naphthoxy) groups was synthesized using versatile route and tested for CO2 separation. Upon oxidation, the sulfone-containing membranes exhibited higher permeability and lower selectivity.

High refractive index materials: A structural property comparison of sulfide‐ and sulfoxide‐containing polyamides

“…Among all designing strategies, structural modification of monomers is the most powerful and versatile techniques for synthesis of processable high performance polymers. In this regard, introduction of flexible bonds, kinked structures, alicyclics, and bulky groups were frequently considered . Another structural modification approach to enhance the processability of rigid‐rod polymers is by modifying the substitution pattern of aromatic units in the main chain .…”

“…Hence, inclusion of n,n ′‐disubstituted biphenylene ( n = 1–3) and 1,2‐linked units derived from ortho ‐catenated aromatic rings are mainly used. Since 2006, our group has started a systematic project to develop processable polymers using various ortho ‐linked sulfide‐, sulfoxide‐, and sulfone‐containing monomers . It was found that the phenyl rings are forced by the ortho ‐linked pattern into a noncoplanar conformation which improves processability through reducing intermolecular forces between the polymer chains and lowering crystallization tendency.…”

“…In this regard, introduction of flexible bonds, kinked structures, alicyclics, and bulky groups were frequently considered. [7][8][9][10][11][12][13][14] Another structural modification approach to enhance the processability of rigid-rod polymers is by modifying the substitution pattern of aromatic units in the main chain. [15][16][17] Hence, inclusion of n,n 0 -disubstituted biphenylene (n 5 1-3) 18 and 1,2-linked units derived from ortho-catenated aromatic rings 11,19 are mainly used.…”