Thermal Analysis of Polyimide-Cobalt Ferrite Nanocomposites
D. Mazuera, O. Perales-Perez, S.P. Singh, O.M. Suarez
University Of Puerto Rico Mayaguez, PR
Keywords: magnetic polymer, nanocomposite, cobalt ferrite, polyimide
Abstract:Thermal stability and thermomechanical behavior of new polymer-based nanocomposite was investigated to assess the viability of the fabrication process. The nanocomposite film consisted of a polyimide (PI) matrix and nanodispersoids of a recently developed high-coercivity cobalt ferrite single crystals 20nm synthesized in aqueous media under size-controlled conditions. FTIR and XRD analyses confirmed the composite formation and the development of expected phases (polymer matrix and nanodispersoids). TGA was used to investigate the temperature of degradation and thermal stability as a function of time of both PI and nanocomposite. The thermal stability experiment revealed a continuous weight loss of the composite with heating time which would suggest an incomplete imidization process, caused by the presence of cobalt ferrite particles, thus producing a shortening in the PI chain length. This behavior was confirmed by DMA measurements of Tan δ and storage modulus M’ as a function of temperature. Finally, a preliminary study of the effect of the volumetric loading and size of the ferrite nanocrystals on the thermal and mechanical properties of the composite is being included in the present work.