Polyamic acid was analyzed using organic solvent SEC (GPC) column,
LF-804.
Polyamic acid is a precursor of polyimide. It is a multi-ionic polymer which
contains positive and negative electric charges. Here, analysis under two
different mobile phases were compared: (1) NMP alone and (2) with LiBr and
phosphoric acid added to NMP. By adding LiBr and phosphoric acid, ionic
interactions was suppressed and this resulted in producing better (sharper)
peak shape.
Sample : 100µL
2. Poly(pyromellitic dianhydride-co-4,4′-oxydianiline),
Column : Shodex GPC LF-804 (8.0mmID*300mm) x 2
Eluent : (30mM LiBr + 30mM H3PO4) in NMP (upper), NMP (lower)
Flow rate : 0.7mL/min
Detector : Shodex RI
Column temp. : 50° C