功能化POSS/磷酸共掺杂高温质子交换膜制备及其性能

Preparation and properties of functionalized polyhedral oligomeric silsesquioxane(POSS)/ polymer electrolyte composite HT-PEM

为提高磷酸掺杂率,增强膜在高温低湿下的质子传导率,同时保证其机械性能,将季铵化八氨苯基笼型聚倍半硅氧烷(QOAPS)与溴甲基化聚芳醚酮和季铵化试剂三甲胺共混,得到含有QOAPS的季铵盐型聚芳醚酮铸膜液,并用流延法制备成膜,再以浸渍方式掺杂磷酸,获得功能化POSS/磷酸共掺杂型聚芳醚酮高温质子交换膜(PA-QPAEK@QOAPS).通过对不同QOAPS掺杂量的质子交换膜的磷酸掺杂量、尺寸稳定性、机械性能和质子传导率进行表征,表明功能化POSS的引入显著提高了膜的磷酸掺杂水平,在较高磷酸含量下,膜仍具有较好的机械强度以及尺寸稳定性.在180℃下,共掺杂型聚芳醚酮膜的质子传导率相较于原始季铵化聚芳醚酮膜提高了56%.

The amount of phosphoric acid doping is crucial to the performance of phosphoric acid doped high temperature proton exchange membrane(HT-PEM). In order to increase the doping amount of phosphoric acid and thus improving the proton conducting performance of poly(aryl ether ketone)(PAEK)-based composite membranes while ensuring sufficient mechanical property, a kind of phosphoric acid doped functionalized POSS/PAEK hybrid membranes was developed. First, quaternized octa(aminophenyl)-POSS(QOAPS) was blended with bromomethylated PAEK(Br-PAEK) polymer. Second, trimethylamine was used as quaternized reagent to prepare quaternized PAEK containing QOAPS(QPAEK@QOAPS). Finally, phosphoric acid was doped into the membrane(PA-QPAEK@QOAPS). The phosphoric acid doping, dimensional stability, mechanical properties and proton conductivity of the protonexchange membranes with different QOAPS doping amounts were characterized, showing that the introduction of functionalized POSS significantly increased the phosphoric acid doping level of the membranes, and the membranes still had good mechanical strength as well as dimensional stability at higher phosphoric acid contents. At 180 ℃, the proton conductivity of the co-doped polyaryletherketone membranes was increased by 56% compared to the original quaternized polyaryletherketone membranes.