Liquid‐crystalline polyurethanes, 6. Amphiphilic polyurethanes containing long alkyl chains in the side chains and amino or quaternary ammonium groups in the main chains

Amphiphilic polyurethanes5a–c,6a–c,10a–cand11a–ccontaining hydrophilic amino or quaternary ammonium groups in the main chain, and hydrophobic ocatadecyl or docosyl groups in the side chain, were synthesized by polycondensation of 2,2′‐octadecyliminodiethanol (3a), 2,2′‐docosyliminodiethanol (3b), bis(2‐hydroxyethyl)methyloctadecylammonium bromide (8) and bis(2‐hydroxyethyl)docosylmethylammonium bromide (9) with a diisocyanate such a hexamethylene diisocyanate (4a), 2,4‐toluylene diisocyanate (4b) and 4,4′‐methylenediphenyl isocyanate (4c). Some of them show a thermotropic liquid‐crystalline state, as determined by DSC and polarizing microscopy.