摘要
用两步法制备了聚酰亚胺2,2′-双(3,4-二羧酸苯基)六氟丙烷二酐(6FDA)-1,3-苯二胺(mPDA).测定了聚合物致密膜的密度、自由体积分率和玻璃化转变温度.制备了不同干纺距离下具有超薄致密皮层的聚酰亚胺中空纤维膜.制备的中空纤维膜在25℃,0.5 MPa下,O2的渗透速率为19.10 GPU,O2/N2分离系数为5.99,CO2的渗透速率为106.34 GPU,CO2/CH4的分离系数为82.00.致密皮层的厚度约为96 nm.考察了操作温度对膜性能的影响,结果表明,随着温度的升高,膜的渗透速率增大,分离系数减小.物理老化对膜性能的实验结果表明,随着老化时间的增加,膜的渗透速率减小,分离系数增大.膜的致密层厚度影响膜的老化性能.
2,2＇-Bis （ 3,4-dicarboxyphenyl ） hexafluoropropane dianhydride （ 6FDA ） -1, 3-phenylenediamine （mPDA） polyimide was synthesized by chemical imidization in a two-step procedure. The density of the polymer dense membrane, the fractional free volume and the glass transition temperature were measured. The ultra-thin hollow fiber membranes with a dense skin were fabricated with different air gap. The hollow fiber membranes have an 02 permeance of 19. 10 GPU and a CO2 permeance of 106. 34 GPU with the O2/N2 selectivity of 5.99 and the CO2/CH4 selectivity of 82. 00 at 25 ℃, 0. 5 MPa. The calculated thickness of the dense skin based on O2 permeance is 96 nm. The temperature effect on the gas separation performance was investigated. The permeances of the O2, N2, CH4 and CO2 increase with an increase in temperature, while the seleetivities of O2/N2 and CO2/CH4 decrease. The physical aging phenomenon of the asymmetric hollow fiber membranes spun with different air gap distances was investigated. The results show the permeance of the ultra-thin membranes sharply decreases and the selectivity increases. And the thickness of the dense skin affected the aging behavior.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第6期1240-1244,共5页
Chemical Journal of Chinese Universities
基金
国家“九七三”计划(批准号:2009CB623405)
国家“八六三”计划(批准号:2006AA05Z315)资助
