Preparation and properties of a poly(2-cyano-1,4-phenylene terephthalamide)/layered silicate nanocomposite

The in situ polymerization method was used to prepare a poly(2-cyano-1,4-phenylene terephthalamide)/ layered silicate nanocomposite with organically-modified clay (Cloisite® 30B, southern clay), which was spun into well-oriented fibers and cast into film in the lyotropic and isotropic state, respectively. The degradation temperature of the nanocomposite (∼550°C) was similar to that of poly (2-cyano-1,4-phenylene terephthalamide) and its strength (and modulus) linearly increased with the amount of the layered silicate in the nanocomposite. The intercalated structure was observed using transmission electron microscopy and X-ray diffraction with an increase in d-spacing of the layered silicate from 18.7 A (the organically modified layered silicate; cliosite 30B) to 21.1 A (nanocomposite). The layered silicate in the nanocomposite was well oriented during fiber spinning and film casting. The normal of the surface of the layered silicate was perpendicular to the fiber axis and the surface of the cast film.