Spectroscopic studies on poly(4,4′-methylenedianiline) salts and their bases

Poly (4,4′-methylenedianiline) (PMDA) salts were prepared by chemical polymerization using different protonic acids. The PMDA bases were obtained by dedoping the corresponding salts using NH4OH. The FT-IR and UV-Vis spectroscopic results have shown the absence of the quinoid structure in PMDA systems, which could be attributed to the presence of methylene spacer in the polymer backbone. The electron paramagnetic resonance (EPR) spectra suggest the presence of polarons in PMDA salts and their bases. There is a rough correlation between the conductivity and yield of PMDA salts, which depends on the counter anion used. The results for PMDA systems are compared with those of related systems and discussed.