自具微孔聚合物PIM-1基热致刚性膜材料的制备及气体分离性能

Preparation and Gas Separation Properties of Polymers of Intrinsic Microporosity PIM-1 Based Thermally Induced Rigid Membranes

以邻苯二酚和丙酮为原料,合成出四羟基化合物5,5′,6,6′-四羟基-3,3,3′,3′-四甲基-1,1′-螺旋双茚满,再与四氟对苯二腈发生聚合反应得到自具微孔聚合物PIM-1。然后,分别在300℃、350℃和400℃对PIM-1膜材料进行热处理得到热致刚性膜材料。利用核磁共振仪(NMR)、凝胶渗透色谱仪(GPC)、红外光谱仪(FTIR)、热重分析仪(TGA)、示差扫描量热仪(DSC)、X射线衍射仪(XRD)和扫描电镜(SEM)对所合成的四羟基化合物、PIM-1聚合物及热致刚性膜材料的结构和性能进行表征,并对其气体分离性能进行了测试。研究表明,所合成PIM-1的玻璃化转变温度为340℃,热分解温度为503℃。适当的热处理可提高PIM-1基热致刚性膜材料的气体分离性能,PIM-1-300对H_2、O_2、N2、CO_2和CH_4的渗透通量分别达到2 865Barrer、1 071Barrer、298Barrer、7 070Barrer和495Barrer。但随热处理温度升高,热交联程度增加,膜材料的气体渗透性逐渐降低,但选择性有所提高。PIM-1-400的CO_2/CH_4分离系数为18.51。

Firstly,5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane was synthesized from catechol and acetone as the raw materials.Then,the intrinsically microporous polymer PIM-1 was prepared from a dioxane-forming reaction between the home-made 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane and 2,3,5,6-tetrafluoroterephthalonitrile.The PIM-1 polymer membranes were thermally treated at 300℃,350℃and 400℃for 1 h under the N 2 atmosphere,respectively.The structures and properties of the tetrahydroxyl compound,PIM-1 polymer and the PIM-1 based thermally induced rigid membranes were characterized by nuclear magnetic resource(NMR),gel permeation chromatography(GPC),differential scanning calorimeter(DSC),thermogravimetric analysis(TGA),Fourier transform infrared(FTIR),X-ray diffraction(XRD)and scanning electron microscope(SEM),and the gas separation properties of these membranes were also measured with five kinds of pure gases,including H 2,O 2,N 2,CO 2 and CH 4.These experimental results showed that the obtained PIM-1 exhibited good thermal properties with the glass transition temperature(T g)of 340℃and the thermal decomposition temperature(T d)of 503℃.The gas permeabilities of the resultant PIM-1 based thermally induced rigid membranes were further improved by controlling the processing temperature.After the thermal treatment at 300℃,the permeabilities of H 2,O 2,N 2,CO 2 and CH 4 of the thermally induced rigid membranes were 2 865 Barrer,1 071 Barrer,298 Barrer,7 070 Barrer and 495 Barrer,separately.Furthermore,with the temperature increasing,the permeabilities of these gas separation membranes were decreased,but the selectivity was improved.For the PIM-1-400 membrane,the selectivity of CO 2/CH 4 was 18.51.