Date of Award
Master of Engineering
Mechanical and Materials Engineering
Dr. D.M. Shinozaki
Nanocomposites were prepared by blending organically modified clay (organo- clay) with poly (vinylidene-fluoride) PVDF in solution. The crystallization conditions of nanocomposites affected both the dispersion of the layered silicates in the matrix and the polymer crystalline morphology in nanocomposites. In the present work it was anticipated that by using a solution blending method, the electroactive polymer crystal phase (P-phase) would be predominantly induced in the matrix during the solidification process. The proportion of crystalline P-phase formed in the nanocomposites was dependent on the samples' preparation conditions. X-ray diffraction was used to investigate the dispersion of layered silicates in the nanocomposites matrix. Intercalated structures were found in nanocomposites with lower clay loadings (0.5% wt) and imiscible structures for higher clay concentration (5% wt). The polymorphism (y and p-phases) developed in the nanocomposites was assessed using x-ray diffraction and Fourier transform infrared spectroscopy (FTIR). The crystalline P-phase was found to be predominant in the nanocomposites recrystallized from the melt. The crystallization kinetics of the matrix were analyzed employing differential scanning calorimetry (DSC). Reinforcing effect of the clay in nanocomposites was determined using dynamic mechanical thermal analysis (DMTA). The study of the nucléation process was also important. It was experimentally found that P-phase formed in the matrix originated from the y-phase nucleated on the clay layers. The nucléation process had been thermodynamically favored in the presence of the modified silicate layers, when the nanocomposites were crystallized at relatively high temperature.
Hodis, Viorel, "PROPERTIES OF SOLUTION BLENDED POLY(VINYLIDENEFLUORIDE)-CLAY NANOCOMPOSITES" (2009). Digitized Theses. 3868.