Radiolytic crosslinking and chain scission in aliphatic and alkyl-aromatic polyamides. Part I

Abstract

The solubility behavior of nine different aliphatic polyamides exposed to ionizing radiation indicates that crosslinking and chain scission yields are independent of dose. Although p 0/q 0 apparently does decrease with increasing methylene content in these polyamides, G(X) and G(CS) appear to depend principally on the methylene content of the amine residue in the repeat units. A comparison of four mixed alkyl-aromatic polyamides indicates that the presence or absence of hydrogen atoms on the carbon atom α to the nitrogen is critical in determining crosslinking propensities. Thus the G(X) value exhibited by poly (imino-1, 3-phenyleneiminosebacoyl) is only about 10% of that of the similar poly (iminomethylene-1, 3-phenylenemethyleneiminosebacoyl) or poly (iminooctamethyleneiminoisophthaloyl) which both exhibit G(X) values in the same range as wholly aliphatic polyamides having a similar methylene content in the amine residue.