Preparation and characterization of novel thermoset polyimide and polyimide-peo doped with LiCF3SO3

Abstract

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.

Effect of the solvent type and polymerization conditions on the curing kinetics, thermal and viscoelastic performance of poly(amide-imide) resins

“…The second intensive peak was observed in the high-temperature range (~400-600°C). It corresponds to the thermal degradation of the PAI resins with onsets at ~430°C for NMP_TC(I) and ~420°C for MI_TC(L), which is in agreement with results of other authors for polyimide-systems [30]. As can be concluded, the thermostability of cured PAI films is marginally influenced by the solvent used.…”

Facile fabrication and characterization of polyimide nanofiber reinforced photocured hybrid electrolyte for Li‐ion batteries

“…The great variation in Tg values is due to the different methods used in polymer synthesis, and the instrument used in analysis. The Tg of pure BTDA/ODA PI fiber was found as 182°C which is much higher than commercially used Celgard 2400 . When UV curable formula applied to PI matrix, the Tg increased due to formation of crosslinked structure, but when Li salt was incorporated to UV‐cured matrix, Tg values decreased due to plastification effect of EC and DMC solvent mixture.…”

“…It can be seen from DSC results that Tg values of the hybrids decrease with the addition of Li salt. In literary texts, there are various Tg values for BTDA/ODA PIs . The great variation in Tg values is due to the different methods used in polymer synthesis, and the instrument used in analysis.…”

“…The frequency ranged from 40 Hz to 100 mHz at a perturbation voltage of 5 mV. The ionic conductivity values of the membranes are calculated from the intercept of the real part of the complex impedance plot, which is resistance of the membrane and known area using eqn : where σ is conductivity, L / A is geometrical factor, L is the thickness of the electrolyte membrane, R is resistance of the electrolyte membrane and A is the area of the membrane.…”

UV-Cured polypropylene mesh-reinforced composite polymer electrolyte membranes

“…(1,2). Work on polymer/salt mixtures has increased during recent years due to the growing interest in these systems as fast ion-conducting systems.…”