| Abstract: | Wholly aromatic rigid‐rod polyamides such as poly(p‐phenyleneterephthalamide) (PPD‐T) were synthesized in situ in a solution of nylon‐6 via the phosphorylation polycondensation method to form nanocomposites or so‐called “molecular composites.” The incorporation of PPD‐T into a nylon‐6 matrix was achieved by this approach in a more compatibilized form than that obtained by the conventional coagulation method that entails precipitation of a blend of PPD‐T and nylon‐6 in a solvent, for example, concentrated sulfuric acid. Gelation occurred during the synthesis, presumably because of the formation of interpenetrating networks accompanied by some block‐copolymer formation. The transparency and tensile properties of the resultant composite films from the rigid‐rod aromatic polyamide/nylon‐6 combination were improved over those of nylon‐6 film alone. Rainbow‐colored intense birefringence was observed for the composite films under crossed polarizers. These properties are discussed in context with the in situ synthesized rigid‐rod polyamides uniformly incorporated in nylon‐6. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1014–1026, 2003 |
