【摘要】：陰離子交換膜燃料電池(Anion Exchange Membrane Fuel Cell, AEMFC)結(jié)合了質(zhì)子交換膜燃料電池結(jié)構(gòu)簡單,堿性燃料電池氧化速度快以及直接甲醇燃料電池高能量密度等一系列優(yōu)點,具有很大的發(fā)展空間。陰離子交換膜(Anion Exchange Membrane, AEM)作為AEMFC的關(guān)鍵組成部分,起到傳遞氫氧根離子同時阻隔燃料和氧化劑的作用。本論文制備了幾種新型的季銨化聚醚砜陰離子交換膜,并且詳細研究了所制備的陰離子膜的基本性能。 首先通過無規(guī)共聚的方法制備了兩種不同結(jié)構(gòu)的聚醚砜聚合物,然后通過傅-克烷基化反應將氯甲基基團分別引入到聚合物分子主鏈和側(cè)鏈上,之后經(jīng)過季銨化及堿化處理制備了一系列聚醚砜陰離子交換膜。實驗結(jié)果表明,采用不同結(jié)構(gòu)單體合成的聚醚砜對膜性能影響較大。以雙酚芴結(jié)構(gòu)單元合成的聚醚砜陰離子膜因其含有剛性較強的雙酚芴單元而具有較好的機械性能及耐堿穩(wěn)定性,并且由于離子基團主要是連在聚合物側(cè)鏈上,有利于聚合物形成親水-疏水微相分離結(jié)構(gòu),利于OH-的傳遞。如rQPES(A)-2膜(IEC=1.33mmol/g)在30℃和80℃水中的離子傳導率分別為10.6mS/cm和41.4mS/cm,在經(jīng)4M NaOH溶液浸泡168h后,離子傳導率的損失在40%左右。另一方面,以雙酚A結(jié)構(gòu)單元合成的聚醚砜陰離子膜rQPES(B)-2膜(IEC=1.26mmol/g)在相同條件下的離子傳導率分別為6.7mS/cm和36.1mS/cm,經(jīng)強堿浸泡后,離子傳導率的損失在50%左右。 然后通過改變合成工藝,采用分步加料方式,成功合成了的序列式聚醚砜陰離子交換膜。對所制備的膜進行了性能表征。結(jié)果表明：IEC值相似時,序列式陰離子膜在離子傳導率、機械性能及耐堿穩(wěn)定性方面均高于無規(guī)型陰離子膜。如sQPES(20/20)-A2膜(IEC=1.72mmol/g)在30℃時的離子傳導率為27.8mS/cm,而rQPES(A)-4膜(IEC=1.78mmol/g)在30℃時的離子傳導率為23.0mS/cm。經(jīng)4M NaOH溶液浸泡168h后,序列式陰離子交換膜離子傳導率的損失在30%左右,而無規(guī)型陰離子交換膜在相同條件下離子傳導率的損失在40%以上 最后以合成的季銨化無規(guī)型聚醚砜聚合物為原料,采用球磨法制備了一系列TiO2納米管摻雜型聚醚砜陰離子交換膜。研究表明,適量TiO2納米管的加入能夠在膜離子傳導率增大的情況下,有效的抑制膜的溶脹,提高膜的尺寸穩(wěn)定性和機械性能。例如QPES(A)-TNT-2.0%摻雜膜,在30℃時在平面方向和厚度方向的尺寸變化分別為0.20和0.19,吸水率為98%,離子傳導率為25.7mS/cm。相比之下,未摻雜膜在30℃時在平面方向和厚度方向的尺寸變化分別為0.25和0.23,吸水率為92%,離子傳導率為23.2mS/cm。這表明納米材料摻雜改性是制備高性能陰離子交換膜一種非常有效的方式。
[Abstract]:The anion exchange membrane fuel cell (Anion Exchange Membrane Fuel Cell, AEMFC) combines a series of advantages, such as simple structure of proton exchange membrane fuel cell, fast oxidation speed of alkaline fuel cell and high energy density of direct methanol fuel cell. There is a lot of room for development. As a key component of AEMFC, the anion exchange membrane (Anion Exchange Membrane, AEM) acts as a barrier to fuel and oxidant at the same time. In this paper, several new quaternary ammonium polyethersulfone anion exchange membranes were prepared and their basic properties were studied in detail. At first, two kinds of polyethersulfone polymers with different structures were prepared by random copolymerization, and then chloromethyl groups were introduced into the main chain and side chain of polymer by Friedel-gram alkylation reaction. A series of polyethersulfone anion exchange membranes were prepared by quaternization and alkalization. The experimental results show that polyethersulfone (PES) synthesized with different structure monomers has great influence on the performance of the membranes. The polyethersulfone anion membrane synthesized with bisphenol fluorene structure unit has good mechanical properties and alkali-resistant stability because it contains a rigid bisphenol fluorene unit, and the ionic group is mainly attached to the side chain of the polymer. It is advantageous to the formation of hydrophilic-hydrophobic microphase separation structure and the transfer of OH-. For example, the ion conductivities of rQPES (A) 2 membrane (IEC=1.33mmol/g) in water at 30 鈩，

本文編號：2402724