Miscibility and Mechanical Properties of Poly(4,4′-diaminobenzanilide- 2,6-naphthalamide)/Nylon 6 Molecular Composites

Poly(4,4′-diaminobenzanilide-2,6-naphthalamide) (DBNA) was synthe-sized by reaction of 2,6-naphthalene dicarboxylic acid with 4,4′-diamino-benzanilide. A new family of molecular composites based on the synthesized DBNA and nylon 6 has been discovered. Exploratory studies were con-ducted with polymers that are soluble in a common organic solvent, N-methylpyrrolidone containing lithium chloride, so that a blend could be prepared by precipitating blended materials in solution into a non-solvent such as water. The miscibility of blends of DBNA with nylon 6 was studied using a differential scanning calorimeter, dynamic mechanical analyser and Fourier transform infrared spectrometer. The blends were found to have at least partial miscibility between DBNA and nylon 6. The morphology and mechanical properties of the molecular composites were evaluated using a scanning electron microscope, transmission electron microscope and tensile tester. The etched specimen showed microfibrils with a diameter of a few nanometres. It has been found that improvement in DBNA dispersion and mechanical properties can be obtained by blending small amounts of DBNA in nylon 6. © of SCI.