Cardo基聚酰亚胺炭膜的制备及CO_(2)分离性能  

Preparation and CO_(2)separation performance of Cardo-based polyimide carbon membrane

作　　者：戴晶 沈子琦 王化江 邱威 汪朝晖[1,2] 汪效祖[1,2] DAI Jing;SHEN Ziqi;WANG Huajiang;QIU Wei;WANG Zhaohui;WANG Xiaozu(College of Chemical Engineering,Nanjing Tech University,Nanjing 210009,China;State Key Laboratory of Materials-Oriented Chemical Engineering,Nanjing 210009,China)

机构地区：[1]南京工业大学化工学院,江苏南京210009 [2]材料化学工程国家重点实验室,江苏南京210009

出　　处：《电力科技与环保》2022年第5期432-438,共7页Electric Power Technology and Environmental Protection

基　　金：国家重点研发计划(2020YFA0211002)。

摘　　要：CO_(2)的大量排放加剧了气候变化,膜法分离气体则是高效环保分离CO_(2)的一种方式。采用两步法,将六氟二酐(6FDA)与9,9-双(4-氨基-3-甲苯基)芴(CH_(3)FDA)进行缩聚,合成了芴基Cardo型聚酰亚胺6FDA-CH_(3)FDA,采用溶剂挥发法制备致密平板膜,并以此为前驱体膜,放置于管式炉内,从室温下以3℃/min的升温速率升温至目标温度,并辅以150 mL/min的氮气保护,采用热化学法制备炭膜。制备出350、450、550、650、750℃一系列炭化温度的6FDA-CH_(3)FDA炭膜,研究了炭化温度对膜结构的影响以及膜气体分离性能的变化。实验结果显示,随着炭化温度的升高,膜的炭化程度越完全,炭膜内部结构越来越致密,有序度不断增加,且炭膜的气体渗透系数呈现先增加后减小的趋势,在炭化温度为650℃时,膜性能最佳,CO_(2)渗透通量(13844.67Barrer)较前驱体膜(166.13 Barrer)增加了82倍,CO_(2)/CH_(4)理想选择性(31.44)较前驱体膜(22.76)增加了64.4%,且远远超过2008年Robeson上限。A large amount of CO_(2) emissions aggravate climate change.Membrane separation is an efficient and environmentally friendly way to separate CO_(2).Fluorenyl Cardo polyimide 6FDA-CH_(3)FDA was synthesized by polycondensation of hexafluorodianhydride(6FDA)and 9,9-bis(4-amino-3-methylphenyl)fluorene(CH_(3)FDA)in a two-step process.Dense flat film was prepared by solve nt evaporati on method,and the film was placed in a tubular furnace as the precursor.The carbon films were prepared by thermochemical method from room temperature at a heating rate of 3℃/min to the target temperature and protected by nitrogen 150 mL/min.6FDA-CH_(3)FDA carbon membranes were prepared at 350℃,450℃,550℃,650℃and 750℃.The influence of carbonization temperature on the membrane structure and the cha nge of membra ne gas separati on performance were studied.The experimental results show that with the in crease of the carbonization temperature,the more complete the carbonization degree of the film,the inner structure of the carbon film becomes more and more compact,the order degree in creases,and the gas permeability coefficient of the carbon film in creases first and then decreases.The film performance is the best whe n the carb onization temperature is 650℃.The CO_(2) permeation flux(13844.67 Barrer)was 82 times higher than that of the precursor membrane(166.13 Barrer),and the IDEAL CO_(2)/CH_(4) selectivity(31.44)was 64.4%higher than that of the precursor membrane(22.76),far exceeding the 2008 Robeson upper limit.

关 键 词：芴基 聚酰亚胺 炭膜 气体分离 CO_(2) 

分 类 号：TQ028.8[化学工程]