Complexes between branched polyethylenimine and NaSO3CF3 were formed with a polymer repeat unit to salt ratio of 6:1, 12:1, and 20:1. All three complexes are amorphous in contrast to linear polyethylenimine which forms partially crystalline complexes at ratios above 6:1 (lower salt concentrations). The 6:1 complex of branched polyethylenimine has a higher Tg (12°C) and a lower conductivity (10-8 S/cm at 40°C) than the corresponding complex of linear polyethylenimine (-5°C and 10-7 S/cm). The glass transition temperature of the polymer-salt complex decreases by 43 deg upon decreasing the salt concentration from that of the 6:1 complex to that of the 20:1 complex. Correspondingly, the conductivity of the 20:1 complex at 40°C is 2 orders of magnitude higher than that of the 6:1 complex. N-H stretching frequencies of linear and branched polyethylenimines and their polymer-salt complexes were studied by infrared spectroscopy. An increase in frequency of the N-H stretching mode of both polymers is seen upon complex formation.
|Number of pages||4|
|Publication status||Published - 1987|
ASJC Scopus subject areas
- Materials Chemistry