To Investigate the Impact of Tailorable Interface on the Morphology and Performance Characteristics of High Temperature Nanocomposites

摘要

Considerable research has been conducted in improving the performance characteristics of nanocomposites, relatively few attempts have been made to address the thermal stability of nanocomposite. This research is focused on the preparation of the layered organosilicates with higher thermal stability, which can be used to make high-temperature polymer nanocomposites. Two approaches to formulate layered organosilicates nanocomposites with higher thermal stability were studied. In the first approach, apophyllite, a pure, natural and commercially-available layered silicate, was treated with 7- octenyltrichlorosilane in order to chemically graft the functional pendent organic group containing a C''C bond. The characterization from Fourier transform infrared (FTIR) spectroscopy, wide-angle x-ray diffraction (WAXD) and thermal gravimetric analysis (TGA) supports that the organic pendant group was successfully covalently grafted in the layered-silicate backbone, and the layered organosilicate is high thermally stable (decomposition temperature: 430 degrees C). In addition, vinyl ester nanocomposites were formulated and mechanical properties evaluated. In the second approach, a pure, natural and commercially-available layered silicate, was treated with synthesizied imidazolium salts. The nanodispersion of imidazolium treated clay in an epoxy matrix was evaluated qualitatively by X-ray diffraction (XRD), transmission electronic microscopy (TEM), confocal laser microscopy, and laser induced fluorescence spectroscopy. Results from the four complimentary techniques enable the characterization of the clay platelets over several length scales ranging from the micrometer to the nanometer scale. Mechanical property evaluation of the nanocomposites are underway.