Tailoring the microporosity and gas separation property of soluble polybenzoxazole membranes derived from different regioisomer monomers
Tailoring the microporosity and gas separation property of soluble polybenzoxazole membranes derived from different regioisomer monomers
复制标题
DOI：
10.1016/j.seppur.2023.123340
复制
发表时间：
2023-02
影响因子：
8.6
通讯作者：
P. Xiao;Xiaojie He;Chao Ye;Songyang Zhang;Feng Zheng;Q. Lu;Xiaohua Ma
中科院分区：
文献类型：
--
作者：
P. Xiao;Xiaojie He;Chao Ye;Songyang Zhang;Feng Zheng;Q. Lu;Xiaohua Ma
新型高分子材料及其分子结构与气体分离性能的关系是气体膜分离技术的关键。以螺双茚烷为结构单元，合成了一系列含双苯并恶唑的二胺，并由此合成了相应的四种可溶性螺双茚烷-双苯并恶唑-聚酰亚胺（SPBO-PI）（5a-6 FDA ~ 5 bb-6 FDA）。这些SPBO-PI表现出上级的溶解性、优异的机械性能（显示出高拉伸强度（约80 MPa）和有吸引力的断裂伸长率（7.6- 12.8%））以及良好的热稳定性（Tg高达491 °C）。主链中含有对位氨基和对称键的SPBO-PI具有上级的热性能和力学性能，密度略低（1.24、1.25 vs1.27、1.29 cm 3g −1），表面积更大（561，437 vs 364，318 m2 g −1），更大的π（5.74，5.60 vs5.53，5.49 π），和更大的自由体积（0.302，0.284 vs0.282，0.277）比相应的mata-氨基和不对称键。对位连接的胺异构体（5a-6 FDA）的SPBO-PI比间位连接的胺异构体（5aa-6 FDA）的SPBO-PI具有更好的CO2/CH 4和CO2/N2分离性能，同时，对称的恶唑异构体（5aa-6 FDA）的SPBO-PI比不对称的恶唑异构体（5 bb-6 FDA）的SPBO-PI具有更高的渗透性。5 b-6 FDA具有较好的抗增塑性能，在20 bar时CO2渗透率为97.3 Barrer，CO2/CH 4混合气体选择性为24.1。SPBO-PI膜的研究为高性能聚酰亚胺和聚苯并恶唑类膜的分子设计提供了理论依据。
New polymers and the relationship between their molecular structure and gas separation performance are crucial in membrane based gas separation. In the study, a range of bisbenzoxazole containing diamines with spirobisindane as building block were synthesized, and consequently, their corresponding four soluble spirobisindane-bisbenzoxazole-polyimides (SPBO-PIs) (5a-6FDA to 5bb-6FDA) were obtained. These SPBO-PIs exhibit superior solubility, brilliant mechanical performance which shows high tensile strengths (about 80 MPa) and attractive elongation at break (7.6–12.8 %), and good thermal stability (Tgup to 491 °C). The SPBO-PIs frompara-amino and symmetric linkages in the polymeric main chains has superior thermal and mechanical properties, slightly lower density (1.24, 1.25vs1.27, 1.29 cm3g−1), higher surface area (561, 437vs364, 318 m2g−1), bigger micropore (5.74, 5.60vs5.53, 5.49 Å), and larger free volume (0.302, 0.284vs0.282, 0.277) than the corresponding mata-amino and asymmetric linkages. The SPBO-PI from amine isomers atpara-linked (5a-6FDA) exhibits better CO2/CH4and CO2/N2separation performance than the SPBO-PI from amine isomers atmeta-linked (5aa-6FDA), meanwhile, the SPBO-PI from symmetric oxazole isomers (5aa-6FDA) shows higher permeability than the asymmetric oxazole isomers (5bb-6FDA). The 5b-6FDA exhibits reasonable anti-plasticization properties, and 97.3 Barrer for CO2permeability and 24.1 of CO2/CH4mixed-gas selectivity at 20 bar. The study about SPBO-PI membranes shed light on molecular design of high performance polyimide and polybenzoxazole-based membranes.