Effect of the organic groups of difunctional silanes on the preparation of coated clays for olefin polymer modification

Sodium montmorillonite (MMT) was organically modified with hexadecyltrimethylammonium ions and subsequently treated with dichlorosilanes and water, aimed at in situ silane condensation polymerization and modification of clay platelets by polysiloxane coatings. Dimethyldichlorosilane, methylphenyldichlorosilane, and diphenyldichlorosilane were used to produce three siloxane-modified organoclays. The structure and morphology of the clay materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric studies (TG) and scanning electron microscopy (SEM). XRD results showed that the silanes were effectively polymerized in the clay galleries, forming a nanocomposite of intercalated particles. A fraction of the siloxane formed is bonded to the clay surface by covalent siloxane bonds. Strong structural differences in both morphology and thermal stability of the materials may occur when changing methyl or phenyl groups in the siloxane structure. The formation mechanism of these intercalated nanocomposite particles is considered. Finally, these modified clays were incorporated in an olefin polymer and morphological analyses using transmission electron microscope (TEM) images were carried out.Fil: Monasterio, Fernanda Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Dias, Marcos L.. Universidade Federal do Rio de Janeiro; BrasilFil: Pita, Victor J. R. R.. Universidade Federal do Rio de Janeiro; BrasilFil: Erdmann, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Destefanis, Hugo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin