填充型具有微孔结构的磺化聚芳醚砜/聚醚砜复合质子交换膜的制备及性能

Preparation and Properties of Filling-type Sulfonated Poly(arylene ether sulfone)/Poly(ether sulfone) Composite Membranes with Microporous Structures

制备了基于磺化聚芳醚砜(SPAES)及聚醚砜(PES)的填充型复合质子交换膜,研究了其吸水率、尺寸变化、热-机械特性、质子电导率、甲醇透过性及稳定性等性能.通过浸入沉淀相转化法,采用磺化度分别为30%(S30),40%(S40)及50%(S50)的SPAES与PES制备了系列微孔型复合质子交换膜Sx-y(x为SPAES的磺化度,y为SPAES的质量分数);然后利用真空抽滤法在微孔中填充S50制备了相应的填充型复合质子交换膜Sx-y+F50.结果表明,由于微孔的引入及皮层结构的存在,Sx-y膜在低离子交换容量(IEC)条件下仍具有较高的电导率、优良的机械强度、优异的化学稳定性及较低的甲醇透过性.经S50填充后,Sx-y+F50膜的IEC及电导率明显提升,甲醇透过率大幅下降,但机械强度及化学稳定性未见劣化.其中S30-40+F50膜(IEC=0. 69 mmol/g)的综合性能最佳,其质子电导率在90℃水中达到50. 4 m S/cm;经140℃水处理24 h后失重率仅为8. 2%,质子电导率降低仅9%;经过芬顿试剂(3%H2O2,20 mg/L Fe SO4,80℃,1 h)处理后失重率仅为0. 66%;甲醇透过率仅为6. 8×10-8cm2/s.

A series of filling-type composite polymer exchange membranes was prepared based on sulfonated poly(arylene ether sulfones)(SPAES) and poly(ether sulfone) s(PES),and the properties including water uptake,dimensional change,thermal-mechanical properties,proton conductivity,methanol permeability and chemical stability were evaluated. Firstly,a series of microporous composite proton exchange membranes(Sx-y,x refers to the sulfonation degree of the SPAES copolymers,y refers to the mass ratio(20%-40%) of SPAES copolymers) was fabricated via immersion phase inversion method from PES and SPAES copolymers with sulfonation degree of 30%(S30),40%(S40) and 50%(S50). Then,the corresponding filling-type composite polymer exchange membranes(Sx-y +F50) were prepared by filling S50 in the Sx-y micropores by vacuum filtration. The results indicate that the Sx-y membranes,despite of the rather low ion exchange capacity(IEC),all display fairly high proton conductivity,fine mechanical strength,excellent chemical stability and rather low methanol permeability. After filling with S50,the corresponding Sx-y +F50 membranes exhibit improved IEC and proton conductivity,lowered methanol permeability,and maintain high mechanical strength and chemical stability. The S30-40+F50 membrane(IEC = 0. 69 mmol/g) shows the best comprehensive properties: proton conductivity of 50. 4 m S/cm at 90 ℃ in water;mass loss of 8. 2% and proton conductivity loss of 9% by aging in water at 140 ℃ for 24 h,and mass loss of 0. 66% by soaking in Fenton reagent(3% H2 O2,20 mg/L FeSO4) at 80 ℃ for 1 h;methanol permeability of 6. 8×10^-8 cm^2/s. The filling-type composite proton exchange membranes are promising candidates for fuel cell applications.