Effect of Isomerism on Molecular Packing and Gas Transport Properties of Poly(benzoxazole-co-imide)s

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• 作者：Yongbing Zhuang ; Jong Geun Seong ; Yu Seong Do ; Hye Jin Jo ; Moon Joo Lee ; Gang Wang ; Michael D. Guiver ; Young Moo Lee
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：November 25, 2014
• 年：2014
• 卷：47
• 期：22
• 页码：7947-7957
• 全文大小：578K
• ISSN：1520-5835

文摘

A facile approach to synthesize poly(benzoxazole-co-imide)s without thermal rearrangement at high temperature is proposed. Poly(benzoxazole-co-imide)s with improved mechanical and solution-processable properties were prepared through polycondensation of 4,4鈥?(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with three synthesized novel benzoxazole-containing diamines and a commercial diamine. These poly(benzoxazole-co-imide)s had high tensile strengths of 110.3鈥?22.0 MPa and good elongation at break of 11.9鈥?6.3%, good thermal stability and high glass transition temperatures (T_gs) of up 306 掳C. The effect of chain isomerism on molecular packing and physical and gas transport properties of the poly(benzoxazole-co-imide)s was investigated. The para-connecting isomers exhibited higher molecular weights (M_ws), better mechanical properties, higher T_gs, higher chain packing order and better overall performance for CO₂/CH₄ and CO₂/N₂ separations as compared to the corresponding meta-connecting ones. This study guides molecular architecture to improve particular membrane separation performance by introducing either para- or meta-connections into polymeric main chains.