Synthesis Of Guanidine, Guanidine Salt Ionic Liquid And Their Applications In Catalytic And Anion Exchange Membranes

Ionic liquids (ILs) are generally defined as organic/inorganic salts with a meltingpoint lower than100oC. The advantages of ILs include good thermal and chemicalstability, negligible vapour pressure, high ionic conductivity, designedphysico-chemical properties, etc. Interestingly, functionalizationed polymers with ILsgroups, which were also named in the scientific literature as poly(ionic liquid)s (PILs),have been pursued as a way of developing a new class of polyelectrolytes.In recent years, ILs, PILs and their related technologies been have found manyapplications in catalytic and electrochemical devices. Guanidine and guanidine saltionic liquid exhibit excellent physical and chemical properties, due to thecharacteristics of their structures. Our main work focused on the application ofguanidine and guanidine salt ionic liquids in catalytic and conductive polymermembranes.The aim of the present thesis is the design and synthesis of catalyst andconductive polymer membrane with superior performance by simple processes.Furthermore, we not only developed simple and rapid synthetic routes andsummarized its mechanism, but also explored them application in the field ofcatalytic, gas capture, gas separation and anion exchange membrane. The specificcontents are as follows:1. The development, synthesis and application of ILs and PILs were reviewed.2. Four kinds of alyl-guanidine (AG) were synthesized and used for thepalladium-catalyzed Suzuki cross-coupling reaction to test the catalytic activity. The influence of the solvent and base were also researched to obtain the optimal reactionconditions. AG4with steric bulk shows the best performance for palladium-catalyzedSuzuki cross-coupling reaction, and this catalytic system could tolerate a broad rangeof functional groups under mild reaction conditions. Results from these studiesindicated that AG acted as a ligand to stabilize the Pd species in Suzukicross-coupling reaction, and gave high yields of coupling products. Moreover, thesereactions can be performed in air condition without any special experimentalprecautions, rendering this method highly attractive for large-scale synthesis.3. Quaternary guanidine group functionalized networks were designed andsynthesized by Pd-catalyzed Suzuki cross-coupling reaction. The porosity of thesepolymers were determined by nitrogen adsorption-desorption isotherms, whichindicated that PON-G-2was microporous with1028m2g-1BET surface area and1.9nm pore size. Moreover, Gas (CO2and N2) adsorption isotherms show their CO2storage was79mg g-1and98mg g-1respectively. Pd nanoparticles supported on thePON-G-2was also prepared by ionic exchange, which exhibits high catalytic activityfor Suzuki cross-coupling reaction between aryl bromide and phenylboronic acid(Yield>95%). Last but not the least, there was no apparent activity decrease after thecatalyst was recycled five times.4. Poly(arylene ether sulfone)s were functionalized with quaternaryguanidinium groups in order to investigate their properties as novel polymerichydroxide exchange membrane materials. The polymers were synthesized viachloromethylation of poly(arylene ether sulfone)s, followed by reactions withpentaalkyllguanidine. PSFG1OH-1.0displayed a high ionic conductivity andPSFG5OH-1.0showed an outstanding alkaline stability in1M NaOH at60oC.5A series of linear quaternary guanidine group functionalized poly(aryleneether sulfone)s anion exchange membrane were prepared. By controlling the feedingratio of pentamethylguanidine vs benzyl chloride groups, we can precisely preserve a certain number of benzyl chloride, which are easy to have chemical cross-linkingwith tetramethylguanidine. The resulting cross-linking anion exchange membranesenhanced the ion conductivity as holding appropriate water uptake rate and swellingrate under high IECs.