Nanocompósitos de polietileno de alta densidade e poliamida-6 com argila bentonita nacional foram preparados por meio do processo de intercalação por fusão. Para a modificação da argila foram utilizados tipos diferentes de sais quaternários de amônio visando sintetizar as argilas organofílicas. As argilas não modificada e modificada com os sais foram incorporadas nas matrizes poliméricas, sendo que foram utilizados procedimentos diferentes para a modificação das argilas: para os nanocompósitos de polietileno, a argila foi preparada com quatro sais quaternários de amônio e para os nanocompósitos de poliamida-6 foi utilizado um único tipo de sal quaternário de amônio, variando-se seus teores para a organofilização da argila. O objetivo desse trabalho foi obter nanocompósitos de polietileno e poliamida-6 e caracterizá-los por microscopia eletrônica de transmissão (MET) e por difração de raios X (DRX). Os resultados indicaram que os sistemas polietileno/argila organofílica apresentaram estruturas de nanocompósitos intercalados e/ou parcialmente esfoliados. Já os sistemas poliamida-6/argila organofílica apresentaram uma morfologia esfoliada com uma predominância de partículas de argilas dispersas na matriz.

Polymeric membranes are attracting attention of researchers and industries due to their lower costs. However, they also have lower mechanical resistance and chemical solvents, when compared with other materials. An improvement of polymer properties can be obtained by adding an inorganic nanoload in the structure. This study produced polyamide 6 / bentonite clay nanocomposites with a nominal content of 3%, and this was used in the processed form and in the organically modified form by cation exchange. The nanocomposites were produced by melt intercalation, and then, the membranes were obtained by the technique of immersion-precipitation. Bentonite, organophilic clay, the material processed in the extruder and the membranes were submitted to the x-ray diffraction (XRD) and infrared spectroscopy (ATR-FTIR). By both techniques, it was possible to prove the organic modification of clay and the change in the crystallinity of the nanocomposites and of the membranes.

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O objetivo deste trabalho foi avaliar o efeito do compatibilizante PE-g-MA (5 e 10%) no comportamento reológico de nanocompósitos de poliamida6/polietileno/argila organofílica, onde a argila foi tratada com um sal quaternário de amônio (Cetremide). Em geral, observou-se que a presença do compatibilizante aumentou o torque da mistura de PA6/PE e que a presença da argila organofílica (2%) sem o compatibilizante não pareceu alterar o comportamento do torque da mistura. Por outro lado, para o nanocompósito com 10% em peso de compatibilizante e com a argila organofílica, verificou-se um aumento significativo do torque em relação às outras misturas, evidenciando maior interação da argila organofílica com as matrizes poliméricas, isto é, maior viscosidade do sistema, promovida provavelmente pela presença do compatibilizante. Os resultados de difração de raio X mostraram que os sistemas apresentaram estrutura intercalada e/ou esfoliada.

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Microporous membranes were synthesized from a polymer nanocomposite material, intercalated montmorillonite clay/nylon 6, by an immersion-precipitation method in a water bath. This membrane was skinless and was composed of cellular pores and sheaflike crystallites, which were interwoven into a bicontinuous structure. In contrast, pure nylon 6, precipitated under the same conditions, yielded a skinned asymmetric membrane. The X-ray diffraction patterns showed that the nanocomposites and the membranes exhibited exfoliated structures. By differential scanning calorimetry, it was observed that the clay probably acted as a reinforcing filler, increasing the crystallinity degree of the nanocomposites, but it was practically unchanged in the membranes. Through photomicrographs obtained by scanning electron microscopy, it was possible to verify that all the membranes exhibited an asymmetric morphology with a welldefined porous structure and a tight skin with a cellular sublayer.

Polymer blend is the name for the physical mixture of two or more polymers and/or copolymers, and this allows the obtention of new materials with superior properties to those of the pure components. The blends have been used in obtaining membranes in order to improve the barrier properties so that it can separate two phases totally or partially, restricting the transport of one or more chemical species. In this work, polymer membranes were obtained from blends of PA6/PPgAA and PA6/PP/PPgAA by phase inversion method and were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was observed through the diffractograms that there were no significant variations in the characteristic peaks of PA6, and through SEM, it was observed the formation of microporous asymmetric membranes, where they showed a surface with higher porosity to the binary and ternary blends and presented smallest pore diameter for binary blends.

In this work, it was produced hybrids organic/inorganic membranes of nylon6 and clay mineral constituted of silicate layers, from the interior of the Paraiba. The sodic clay was used in the untreated and treated (with quaternary ammonium salts) form (to become compatible with polymer). Commercial salts Genamin and Cetremide were used to prepare organoclay by cationic exchange reaction in aqueous phase. The nanocomposites were obtained by melt intercalation and from these nanocomposites it was synthesized the membranes for dissolution in predetermined amounts of formic acid and a precipitation in a non-solvent, also called immersion-precipitation technique to prepare thin films. Thus, on the basis of the results, it can be observed that the presence of the treated and untreated clay confer a significant alteration in the structure/morphology of the pores and the porosity of the membrane.