This thesis covers two area of data containg theoretical studies and experimental data. Theoretical studies contain three projects that explore effects of types of proton donor groups, polymer main chain functional groups and degradation mechanism of membranes in presence of radical species. At the first project, proton transfer in sulfonated and phosphonated poly(oxadiazole)s was invesitaget also synergetic effect of other protogenic groups with sulfonate and phosphonte groups was studied compeletly. In the second project, the effect of functional groups in polymer backone on proton transfer was investigated and it was found that some heteroaromitcs such as poly(benzimidazole) and poly(oxadiazol) and also polyimide could facilitate proton transfer in low humidity conditions. In the thired theortitical project, degredation mechanisms of sulfonated poly(polybenzimidazole) in presence H and OH radiclals was studied completely and suggested different deratation mechanisms. In the second part of thesis which cover experimental results, three projects were done. In the first experimental project, a new diol was synthesized and consequently a new poly(ether sulfone) was prepared. A new sulfonated polymer hybride was prepared from synthesized poly(ether sulfone) and commercial poly(ether sulfone) Udel and used as proton exchange membrane in low hymidity condition. Second experimental project focused on synthesis of membranes based on semi-I to improve mechanical properties of membranes in fully hydrated conditions. Also, the prepared membranes show very good chmical stability in fenton’s reagent. In the thired project, natural wasts was used to prepare ion exchange membrane. Ostrich eggsell membranes were modified by two different methods. The modified membranes were employed as both anion and proton exchange membranes and show good performance. Regarding network structre of membranes, there was a concern about fuel crossover in membranes but the modified membranes shows very low fuel crossover.
