Obtenção de membranas de poliamida 6 e de seus nanocompósitos com argila.

Abstract

In this work, polymer membranes were produced from of nylon 6 (Ny6) and a clay consisting of silicates layer from of Paraiba/Northeast of Brazil by immersion-precipitation technique. The clay was organically modified using three different quaternary ammonium salts, Dodigen, Genamin and Cetremide and, this modification was evaluated by XRD that showed the insertion of the salts molecules into silicates layer. Nanocomposites were obtained by nylon 6 with untreated clay (MMT) or treated clay with the salts (OMMT). Firstly, it was obtained a master, 1:1 (Ny6/clay) and this was incorporated in the polymer matrix, using close to 3 wt.% of clay, in a contra-rotational twin screw extruder. The nanocomposites were studied by XRD, TEM, TG and DSC. It was verified that these presented thermal stability and a morphological structure composed of exfoliated/partially exfoliated or intercalated clay layers in the Ny6 matrix. The membranes were produced by inversion phase method, using immersionprecipitation technique. An asymmetric morphology was obtained and analyzed by SEM. It composed by two layers, a "skin" and porous. The top and bottom surfaces showed porous size and distribution uniforms. Hence, microporous membranes were obtained with success from of nylon 6/regional clay nanocomposites. It also was observed that the water presence (used in the solution of preparation of the membranes, acid:water) and clay altered the membrane morphology, decreasing the porous size. The water permeability was analyzed and it was observed that the water flux was reduced significantly due to membrane swelling and large hygroscopicity, which is characteristic of nylon.