Polyamides based on diamines and N, N′-dimethyldiamines derived from biphenol

Aromatic‐aliphatic polyamides containing a biphenyl mesogen were prepared by both interfacial and solution polymerization reactions. Substitution of the amide nitrogen with methyl groups yielded polymers with significantly different properties than the unsubstituted polyamides. The methyl‐substituted polyamides had improved thermal stability, significantly lower meltin temperatures, and greater solubility in common solvents. Copolyamides were also synthesized which contained different flexible spacer units that varied in the number of methylene groups. No evidence for the presence of liquid crystalline phases could be obtained in either the unsubstituted polyamides or polyamides containing N‐methylated amide units. © 1994 John Wiley & Sons, Inc.