Abstract:
Linear copolyesters containing amide groups are obtained by polycondensing certain dicarboxylic acid diamides which are obtained by reacting 1 mol of a N-heterocyclic-aliphatic diamine with 2 mols of terephthalic acid, isophthalic acid or amideforming derivatives thereof, to a relative viscosity higher than 1.2, with terephthalic acid, isophthalic acid or polyesterforming derivatives and with alkanediols. The new copolyesters containing amide groups are valuable engineering thermoplastic materials which can be easily processed and which yield moulded materials with good thermomechanical properties.