侧链型磺化聚砜的制备及侧链链长对质子交换膜性能影响的研究

Preparation of side-chain-type sulfonated polysulfone and preliminary exploration the effect of side chain length on properties of proton exchange membrane

以氯乙酰氯和氯丁酰氯为亲电试剂,通过Friedel-Crafts酰基化反应,在聚砜(PSF)主链引入了含氯的且碳原子数目不同的(分别为2和4)柔性侧链,然后以对羟基苯磺酸钠(HBSS)为试剂,通过亲核取代反应制备了侧链型磺化聚砜2PSF-BSS和4PSF-BSS。采用佛尔哈德分析法、红外光谱(FT-IR)以及核磁氢谱(1HNMR)对侧链型磺化聚砜的化学结构和性能进行了表征,重点考察主要因素对Friedel-Crafts酰基化和亲核取代反应的影响,实验结果表明:以无水Al Cl3为催化剂,CH2Cl2为反应溶剂,反应温度50℃,CAPSF和CBPSF中氯含量分别达到2.03mmol/g和2.07mmol/g,第2步亲核取代反应遵循SN1机理,在强极性溶剂DMSO中磺酸基键合量分别为1.48mmol/g和1.46mmol/g。同时初步探索侧链链长对质子交换膜的质子传导率的影响,随着侧链长度的增长,侧链的柔性增强,亲水微区与疏水微区微相分离的程度增强,导致交换膜的质子传导率增大。

With chloroacetyl chloride and chlorobutyryl chloride as electrophilic reagents,a flexible side chain with exchangeable chlorine was bonded on the backbone of polysulfone（ PSF） via Friedel-Crafts acylation reaction. Subsequently,with sodium 4-hydroxybenzenesulfonate（ HBSS） as reagent,two kinds of sulfonated polysulfones with side-chain-type（ 2PSF-BSS and 4PSF-BSS）were obtained via nucleophilic substitution. The chemical structure and properties of the target polymer PSF-sas were characterized by Vilhard methods,FT-IR and1H-NMR. The effects of various factors on the Friedel-Crafts acylation reaction and nucleophilic substitution reaction were mainly investigated. The experimental results show that the degree of chloride（ DC） of CAPSF and CBPSF could reach to 2. 03 mmol/g and 2. 07 mmol/g at 50℃ with Al Cl3（ 0. 90 g） as catalyst and CH2Cl2 as solvent,respectively. The second step is a unimolecular nucleophilic substitution reaction,i. e. SN1. CAPSF-sas with a sulfonate bonding amount of 1. 48 mmol/g and CBPSF-sas sulfonate with a sulfonate bonding amount of 1. 46 mmol/g were obtained with dimethyl sulfoxide（ DMSO） as solvent. At the same time,the relationship between the length of the side chains and proton conductivity was preliminary explored. Along with the increase of the length of the side chains,the flexibility of the side chains strengthens and the degree of microphase separation increases. It leads to the increase of the proton conductivity of the proton exchange membranes.