Synthesis and CO2 permeation properties of novel sulfonium-substituted poly(diphenylacetylene)s

• Published in: Polymer bulletin (Berlin, Germany) Vol. 75; no. 7; pp. 3011 - 3022
• Main Authors: Sakaguchi, Toshikazu, Kaji, Shintaro, Hashimoto, Tamotsu
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2018; Springer Nature B.V
• Subjects: Carbon dioxide; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Energy consumption; Heat resistance; Membrane separation; Molecular weight; Organic Chemistry; Original Paper; Permeability; Physical Chemistry; Polymer Sciences; Polymerization; Polymers; Potassium; Soft and Granular Matter; Gas permeability; Membrane; Gas separation; Poly(diphenylacetylene); Sulfonium
• ISSN: 0170-0839; 1436-2449
• DOI: 10.1007/s00289-017-2195-8

Substitution of thiourea to poly(diphenylacetylene) having 2-bromoethoxy groups ( 2a ) gave an sulfonium-containing poly(diphenylacetylene) [ 3a (Br − ) ]. The counteranions of 3a (Br − ) could be exchanged using CF 3 COOK and (CF 3 SO 2 ) 2 NLi, and the polymers 3a (TFAc − ) and 3a (Tf 2 N − ) were obtained. Polymer 3a (Br − ) was hydrolyzed with NaOHaq to afford the polymer 4a possessing mercapto groups. The CO 2 permeability coefficients ( P CO 2 ) and the separation factor ( P CO 2 / P N 2 ) of 3a (Br − ) were 15 barrers and 16, respectively. The selectivity was low compared to the analogous polymer, poly(diphenylacetylene) having imidazolium salts ( P CO 2 / P N 2 = 44 ), because 3a (Br − ) interacted strongly with CO 2 , and the diffusion of CO 2 was suppressed. The P CO 2 and P CO 2 / P N 2 of 3a (TFAc − ) were 43 barrers and 24, respectively, and those of 3a (Tf 2 N − ) were 52 barrers and 26, respectively. Both permeability and selectivity increased as the counteranion became bulkier. The mercapto group containing poly(diphenylacetylene) ( 4a ) showed a relatively high CO 2 permeability ( P CO 2 = 130 barrers).