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Abstract. This paper deals with the synthesis and characterization of a new type of anhydrous ionic conducting lithium doped membranes consist of polyimide (PI), poly (ethylene oxide) (PEO) and lithium trifluoromethanesulfonate (LiCF 3 SO 3 ) for solid polymer electrolyte (SPE). For this purpose, different molar ratios of lithium salt (Li-salt) solution are added into poly (amic acid) (PAA) intermediate prepared from the reaction of 3,3!,4,4!-benzophenon tetracarboxylic dianhydride (BTDA) and 4,4!-oxydianiline (ODA). PEO is incorporated into PAA since it forms more stable complexes and possess high ionic conductivities. Then, Li-salt containing PAA solutions are imidized by thermal process. The effect of interaction between host polymer and Li-salt is characterized by FT-IR (Fourier Transform Infrared) spectroscopy and SEM (scanning electron micrsocopy). The conductivities of Li-salt and PEO containing PI composite membranes are in the range of 10 -7 -10 -5 S·cm -1 . The conductivity increases with incorporation of PEO. Thermogravimetric analysis results reveal that the PI/PEO/LiCF 3 SO 3 composite polymer electrolyte membranes are thermally stable up to 500°C.

In this study, a series of novel superhydrophobic polyimide-siloxane electrospun mats was prepared using an electrospinning process. Segmented polyimide-siloxane copolymers were prepared using 4,4 0 -oxydianiline (ODA) and 3,3 0 ,4,4 0 -benzophenone tetracarboxylic dianhydride (BTDA) as hard segments and aminopropyl terminated polydimethylsiloxane (APPS) and BTDA as soft segment. The polyimide-siloxane copolymers were synthesized by varying the APPS loading (10 and 20 mol%) and also the molecular weight of APPS (1000 and 2500 g/mol), respectively. Electrospinning of the polyamic acids was followed by thermal imidization to construct the electrospun polyimide-siloxane mats. The electrospun mats were characterized by FTIR, scanning electron microcopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC) and contact angle measurement. According to SEM results, the polyimide-siloxane electrospun mats have nano-roughness morphology. Bead on string type surface morphology that has been generated by electrospinning yields stable superhydrophobicity with a contact angle of 167°.