Pentiptycene-Based Polyurethane with Enhanced Mechanical Properties and CO2-Plasticization Resistance for Thin Film Gas Separation Membranes

Ali Pournaghshband Isfahani; Morteza Sadeghi; Kazuki Wakimoto; Binod Babu Shrestha; Rouhollah Bagheri; Easan Sivaniah; Behnam Ghalei

doi:10.1021/acsami.7b18475

Pentiptycene-Based Polyurethane with Enhanced Mechanical Properties and CO₂-Plasticization Resistance for Thin Film Gas Separation Membranes

ACS Appl Mater Interfaces. 2018 May 23;10(20):17366-17374. doi: 10.1021/acsami.7b18475. Epub 2018 May 11.

Authors

Ali Pournaghshband Isfahani¹, Morteza Sadeghi², Kazuki Wakimoto¹, Binod Babu Shrestha¹, Rouhollah Bagheri², Easan Sivaniah¹, Behnam Ghalei¹

Affiliations

¹ Institute for Integrated Cell-Material Sciences (iCeMS) , Kyoto University , 606-8501 Kyoto , Japan.
² Department of Chemical Engineering , Isfahan University of Technology , Isfahan 84156-83111 , Isfahan , Iran.

PMID: 29708720
DOI: 10.1021/acsami.7b18475

Abstract

The development of thin film composite (TFC) membranes offers an opportunity to achieve the permeability/selectivity requirements for optimum CO₂ separation performance. However, the durability and performance of thin film gas separation membranes are mostly challenged by weak mechanical properties and high CO₂ plasticization. Here, we designed new polyurethane (PU) structures with bulky aromatic chain extenders that afford preferred mechanical properties for ultra-thin-film formation. An improvement of about 1500% in Young's modulus and 600% in hardness was observed for pentiptycene-based PUs compared to the typical PU membranes. Single (CO₂, H₂, CH₄, and N₂) and mixed (CO₂/N₂ and CO₂/CH₄) gas permeability tests were performed on the PU membranes. The resulting TFC membranes showed a high CO₂ permeance up to 1400 GPU (10^-6 cm³(STP) cm^-2 s^-1 cmHg^-1) and the CO₂/N₂ and CO₂/H₂ selectivities of about 22 and 2.1, respectively. The enhanced mechanical properties of pentiptycene-based PUs result in high-performance thin membranes with the similar selectivity of the bulk polymer. The thin film membranes prepared from pentiptycene-based PUs also showed a twofold enhanced plasticization resistance compared to non-pentiptycene-containing PU membranes.

Keywords: CO2 capture; CO2 induced plasticization; gas separation membranes; pentiptycene; polyurethane; thin film composite.