MODIFICATION OF NYLON-6 WITH WHOLLY RIGID POLY(META-PHENYLENE ISOPHTHALAMIDE)

In this study, the flexible nylon-6 was reinforced by the wholly rigid aromatic polyamide poly (m-phenylene isophthalamide) (PmIA) (Nomex) by physical polyblending and chemical copolymerization using p-aminophenylacetic acid (P-APA) as a coupling agent. From DSC measurements, it was shown that T(g) of the polyblends increased with the increase of Nomex content. The T(g) and T(m) of multiblock copolyamides were found to be higher than those of polyblends and triblock copolyamides. Scanning electron microscopy revealed that the polyblends were a dispersed phase structure, although the multiblock copolyamides exhibited a homogeneous texture rather than an aggregated one. From the wide-angle X-ray diffraction pattern, it was found that the triblock copolyamides and polyblends had two diffraction peaks, i.e., 2 THETA = 20.5 and 24-degrees. However, the multiblock had only one at 2 THETA = 20-degrees, indicating a different crystal structure for multiblock copolyamides. For the mechanical properties, it was found that the multiblock copolyamides had a more significant reinforcing effect than those of polyblends and triblock copolyamides.