Preparation and physicochemical characterization of hybrid nanocomposites from POSS nanomaterials

PREPARATION AND PHYSICOCHEMICAL CHARACTERIZATION OF HYBRID POLYAMIDE NANOCOMPOSITES FROM POSS NANOMATERIALSNilüfer Kıvılcım (Kiğılı)İnönü UniversityGraduate school of Natural and Applied SciencesChemistry Departmentxiv + 146 pages2008Mentor: Prof.Dr. Turgay SEÇKİNThe sol-gel process has been employed to generate hybrid inorganic-organic network materials. Unique ceramers were prepared based on an alkoxysilane functionalized soft organic polyamides and octa functionalized polyhedralsilsesquiones (POSS). Despite the formation of covalent bonds between the inorganic and organic constituents, the resulting network materials composed of a silicate rich phase embedded in a matrix of the organic polyamide chains. The behavior of such materials was similar to elastomers containing reinforcing filler. The study focused on the influence of inorganic filler content on the final structure and thermal properties of polyamides. The sol-gel approach has also been exploited to generate novel polyamides in which Ti(OiPr)4 and Zr(OBu)4 were used to generate novel monomers. These systems were based on alkoxysilane functionalized L-Lysine, which generated hybrid, networks with very high crosslink densities. In another study, intercalated polymer?clay nanocomposites were prepared based on various polyamide networks and clay. This work explored the influence of incorporated clay on the thermal properties of polyamides. The thermal strength increased with increasing clay content. Also, the pure intercalated nanocomposite structure could not be generated. Instead, all nanocomposite systems possessed an either intercalated or delaminated. The final project involved the characterization of a series of chrysotile surface functionalized with g-aminopropoyltriethoxysilane (APS), and its surface polymerization with polyamides. Polyamides synthesized with such new systems are structurally elucidated with differential thermal analysis (DTA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) as well other conventional techniques.Keywords: POSS, Polyamide, Layered Silicates, Surface modification, Sol-Gel Chemistry, Nanomaterials, Nanocomposites