Amorphe Polyamide aus Terephthalsäure und verzweigten Diaminen

Abstract

A group of new terephthalic polyamides based on highly branched hexamethylene diamines is described. Several routes are given for the preparation of diamines bearing methyl and ethyl sidegroups. The compounds obtained are discussed in terms of structural isomerism and their polycondensation with terephthalic acid is performed according to interfacial and block condensation methods. The resulting polymers are characterized by melting points and viscosity in solution.
A typical representative of this new polyamide group, the condensation product of terephthalic acid with trimethyl hexamethylene diamine, has been proved to be permanently amorphous through differential thermal analysis and X-ray investigation. Numerous data on physical and chemical properties are given for this special polyamide and characteristic differences relative to commercial polyamides are unveiled. The development of colour centres in the solid polymer under shear deformation or γ-ray exposure is discussed in terms of trapped radical formation.