作者：Dajie Zhang, Jong Geun Seong, Won Hee Lee, Shinji Ando, Yinhua Wan, Young Moo Lee*, Yongbing Zhuang*
关键字：Polyimides Sulfonation Gas separation
论文来源：期刊
具体来源：Polymer, 191 (2020) 122263
发表时间：2020年

This study presents the effects of sulfonate incorporation and

structural isomerism of soluble sulfonated polyimides (SPIs) for

potential membrane applications. The fluorinated dianhydride (6FDA) and

three commercially sulfonated diamines,

2,4,6-trimethyl-3,5-diaminobenzenesulfonic acid (tDSA), 2,5-diaminobenzenesulfonic acid (pDSA), and 2,4-diaminobenzenesulfonic acid (mDSA),

were used to synthesize SPIs in a one-step polycondensation. The SPIs

are soluble in common organic solvents and have good mechanical

properties as represented by tensile strength of 88.4–115.8 MPa and

elongation at break of 10.3–15.2%. The resulting SPI membranes exhibit

low dielectric constants (~2.61) and linear thermal expansion

coefficients (CTE) ranging from 54.6 to 71.7 ppm/K. These SPI membranes

have fractional free volume (FFV) of 0.119–0.148. The sulfonation incorporation induced closer inter-chain packing, smaller FFV, larger CTE, higher average refractive indices (nav), better transparency and higher ideal selectivities for almost all gas pairs for their membranes. The para-linked TEA-pSPI membrane exhibited a larger inter-chain d-spacing, larger FFV, larger CTE, smaller nav and slightly higher permeability coefficients than the corresponding meta-linked TEA-mSPI

membrane. This study guides molecular architecture for improving

particular membrane performance by introducing sulfonation groups as

well as adjusting either para- or meta-linkages into polymeric main chains.

https://www.sciencedirect.com/science/article/abs/pii/S0032386120301038