發(fā)布時(shí)間：2018-12-16 12:10

【摘要】：質(zhì)子交換膜燃料電池可直接將氫氣、甲醇等化學(xué)能源不經(jīng)卡諾循環(huán)直接轉(zhuǎn)化為電能,具有工作原理簡單,綠色、高效的優(yōu)點(diǎn)。商業(yè)化的質(zhì)子交換膜(PEM)主要是以Nafion膜為代表的全氟磺酸膜。此類膜具有質(zhì)子傳導(dǎo)率高、化學(xué)穩(wěn)定性好和熱性能優(yōu)異的優(yōu)點(diǎn),但是其高成本、高的甲醇透過率阻礙了其在直接甲醇燃料電池中的應(yīng)用。因此,研究制備新型芳雜環(huán)聚合物質(zhì)子交換膜以替代全氟磺酸膜已成為目前的研究熱點(diǎn)。本文以制備交聯(lián)型芳雜環(huán)質(zhì)子交換膜為出發(fā)點(diǎn),制備了共價(jià)交聯(lián)聚倍半硅氧烷(POSS)/磺化聚酰亞胺質(zhì)子交換膜以及離子交聯(lián)磺化聚醚醚酮質(zhì)子交換膜,以期降低傳統(tǒng)芳雜環(huán)質(zhì)子交換膜甲醇透過率。研究交聯(lián)結(jié)構(gòu)對質(zhì)子傳導(dǎo)、機(jī)械性能、阻醇性能等的影響。具體研究工作如下：1.通過控制交聯(lián)劑八氨基倍半硅氧烷(OAPS)的含量(0.2～1.6 mol%)合成了一系列不同交聯(lián)度的八氨基倍半硅氧烷(OAPS)共價(jià)交聯(lián)磺化聚酰亞胺(SPIs)質(zhì)子交換膜。研究發(fā)現(xiàn),POSS交聯(lián)結(jié)構(gòu)在提高所得材料機(jī)械性能和化學(xué)穩(wěn)定性的同時(shí),降低了其甲醇透過率。另外,POSS的存在促進(jìn)了有機(jī)-無機(jī)微相分離結(jié)構(gòu),提高了所得膜的質(zhì)子傳導(dǎo)率。在20-80℃、100%濕度下,所制得的交聯(lián)型薄膜具有和Nafion 117膜相當(dāng)?shù)馁|(zhì)子傳導(dǎo)率。所得的薄膜具有比Nafion膜更低的甲醇透過率。當(dāng)OAPS的含量為0.4 mol%時(shí),80℃下質(zhì)子傳導(dǎo)率為0.111S cm-1,高于Nafion膜(0.10 S cm-1)。2.將二氮芴結(jié)構(gòu)引入到磺化聚醚醚酮(SPEEK)主鏈結(jié)構(gòu),通過磺酸基與二氮芴結(jié)構(gòu)中的吡啶環(huán)的酸堿相互作用得到具有離子交聯(lián)結(jié)構(gòu)的質(zhì)子交換膜。所制得的薄膜具有良好的機(jī)械性能、熱穩(wěn)定性能、氧化穩(wěn)定性以及尺寸穩(wěn)定性。此外,和Nafion 117膜相比,該類離子交聯(lián)型質(zhì)子交換膜具有更低的甲醇透過率(0.56×10-7～1.8×10-7cm2 s-1)。30 ℃時(shí),相對選擇性(2.46～4.82×104 Ss·cm-3)明顯高于Nafion膜(1.34×104Ss·cm-3)。80 ℃時(shí),磺化度為80%的磺化聚醚醚酮薄膜的質(zhì)子傳導(dǎo)率為8.1 mS cm-1,達(dá)到了應(yīng)用要求。
[Abstract]:Proton exchange membrane fuel cells can directly convert hydrogen, methanol and other chemical energy into electric energy without Carnot cycle. It has the advantages of simple working principle, green and high efficiency. Commercial proton exchange membrane (PEM) is mainly perfluorinated sulfonic acid membrane represented by Nafion membrane. This kind of membrane has the advantages of high proton conductivity, good chemical stability and excellent thermal performance, but its high cost and high methanol transmittance hinder its application in direct methanol fuel cells. Therefore, the preparation of novel aromatic heterocyclic polymer proton exchange membranes to replace perfluorinated sulfonic acid membranes has become a hot research topic. Based on the preparation of cross-linked aromatic heterocyclic proton exchange membranes, (POSS) / sulfonated polyimide proton exchange membranes and ion crosslinked sulfonated polyether ether ketone proton exchange membranes were prepared. In order to reduce the methanol transmissivity of the conventional aromatic heterocyclic proton exchange membrane. The effects of crosslinking structure on proton conduction, mechanical properties and alcohol resistance were studied. The specific research work is as follows: 1. A series of (OAPS) covalent crosslinked sulfonated polyimide (SPIs) proton exchange membranes with different crosslinking degrees were synthesized by controlling the content of octamine-octa-trisiloxane (OAPS) (0.21.60 mol%). It is found that the crosslinking structure of POSS can improve the mechanical properties and chemical stability of the materials and decrease the methanol transmittance. In addition, the existence of POSS promotes the separation structure of organic-inorganic microphase and increases the proton conductivity of the membrane. At 20-80 鈩，

本文編號：2382312