含甲基磺化杂萘联苯聚醚砜酮质子交换膜材料的合成与性能

以4-(3,5-二甲基-4-羟基苯基)2,3-二氮杂萘-1-酮,3,3′-二磺酸钠-4,4′-二氟苯甲酮和4,4′-二氯二苯砜为原料,利用亲核缩聚反应,通过改变磺化单体的含量,制备出一系列不同磺化度的杂萘联苯聚醚砜酮(SPPESK-DM).采用FTIR、1H-NMR表征了聚合物的结构,热失重分析仪研究了聚合物的耐热稳定性,以N-甲基-2-吡咯烷酮为溶剂采用溶液浇铸法成膜研究该系列聚合物膜的性能.结果表明,SPPESK-DM磺酸基的热分解温度在260℃以上,主链分解温度在410℃以上;膜的吸水率、溶胀率、离子交换容量和质子传导率均随着磺化度的增大而增大,磺化度为1.0的SPPESK-DM50的质子传导率达到1.08×10-2S/cm(85℃),且甲醇渗透系数为2.06×10-7cm2/s,低于Nafion117膜的甲醇渗透系数(2×10-6cm2/s).此系列膜的耐氧化性比较优异,可望用于质子交换膜燃料电池中.

SYNTHESIS AND PROPERTIES OF SULFONATED POLY(ETHER SULFONE KETONE)S CONTAINING 3,5-DIMETHYL PHTHALAZINONE MOIETIES AS PROTON EXCHANGE MEMBRANE MATERIALS

A series of sulfonated poly(phthalazinone ether sulfone ketone) copolymers,SPPESK-DMs,with different degree of sulfonation(SD) were synthesized by polycondensation of 4-(3,5-dimethyl-4-hydroxyphenyl)-2,3-phthalazinone,3,3′-disulfonate-4,4′-difluorobenzophenone and 4,4′-dichlorodi-phenylsulfone,which were potentially utilized as membranes in proton exchange membrane fuel cells(PEMFC).The high molecular weight sulfonated polymers(SPPESK-DMs) with the inherent viscosity ranged from 1.36 dL/g to 6.04 dL/g were obtained when the sulfonation degree of samples varied from 0.2 to 1.0.The yellow transparent membranes cast from N-methyl-2-pyrrolidone solutions of SPPESK-DMs were obtained.The chemical structure of the sulfonated polymers was characterized by FTIR and ～1H-NMR,the thermo-behavior of polymers was also investigated by TGA,and the properties of the membranes were investigated too.The results indicated that the decomposition temperatures of the sulfonic group and the main chain in the SPPESK-DMs copolymers were above 260℃ and 410℃ respectively,which demonstrated the copolymers had excellent thermal stability.The water uptake,swelling ratio,ion exchange capacity and proton conductivity increased with increasing of temperature and SD.The proton conductivity of the SPPESK-DM50 with the SD of 1.0 was 1.08×10～(-2) S/cm at 85℃,which was considerably lower than that of Nafion 117,but would meet the lowest requirement in PEMFC application.The methanol permeability values of SPPEK-DMs membranes were lower than that of Nafion117.The oxidative stability of the SPPESK-DMs membranes was better than that of SPPEK or SPPESK membranes,and the expended time that membranes started to break into pieces at 80℃ in Fenton's reagent was longer than 4.33 h.