Self‐regulating polycondensations: Ordered aromatic polyamide‐esters

Abstract The polycondensation of aminophenols with diacid chlorides was examined to determine if the amide‐ester polymers obtained are random or ordered. All of the evidence obtained points to the conclusion that ordered copolymers indeed are prepared and that a “self‐regulating” polymerization process is operating by virtue of the considerably greater reactivity of aromatic amino groups relative to phenol groups. The first step of the reaction involves the in situ preparation of a diphenol‐amide which undergoes further condensation. The diphenol‐amide intermediate may be isolated or reacted in situ. In addition to the ordered polymer from a given aminophenol and a single diacid chloride, ordered copolymers from two different diacid chlorides were prepared in which the diacid moieties appear in an alternating fashion; the structure of such polymers depends on the order of addition of the diacid chlorides. Corresponding polymers also may be prepared from the preformed diphenol‐amide monomers. The molecular weights of certain of the polymers were sufficient for the preparation of films which could be hot‐stretched severalfold. Interfacial polycondensations gave polymers of higher inherent viscosities than did solution polymerizations when aminophenols or diphenol‐amide monomers were condensed with diacid chlorides.