Properties and morphology of PPTA/nylon composites

Abstract

Polymer-polymer composite of nylon and poly(p-phenylene terephthalamide) (PPTA) was prepared by in-situ polymerization of p-phenylene diamine and terephthaloyl chloride in nylon solution of nylon terpolymer and N-methyl 2-pyrrolidone (NMP). Nylon terpolymer of nylon 6, nylon 6,6 and nylon 12 was used to enhance the solubility in NMP. For the PPTA/nylon composites, the shift of the glass transition temperature of nylon to a higher temperature was observed was observed, which implied a molecular level mixing of PPTA in nylon matrix. The structure of PPTA in the composite was unchanged although that of nylon was changed considerably by the addition of even 20% PPTA. Electron microscopy revealed that microfibrils of PPTA were homogeneously dispersed in the nylon matrix. The large increase of the melt viscosity with the increase of PPTA content was also observed with rheometric dynamic spectrometer (RDS). The mechanical properties such as Young’s modulus and yield stregth were remarkably improved with the addition of PPTA.