Abstract

GORDILLO DELGADO, Fernando  and  HERNANDEZ ZARTA, Hector Hernán. Thermal Characteristics of TIO₂ Nanocomposite in a Polyurethane Matrix Made with Castor Oil. Rev. ing. univ. Medellín [online]. 2021, vol.20, n.39, pp.147-165.  Epub June 28, 2022. ISSN 1692-3324.  https://doi.org/10.22395/rium.v20n39a9.

Nanocomposites are multiphase structures with at least one phase dimension of nanometric order size. Polymer-based materials mixed with low proportions of titanium dioxide nanoparticles (NPs-TiO2) are a versatile alternative in different industrial applications, considering the optimization of mechanical and thermal properties with respect to pure polymers and conventional materials. In this work, the synthesis and thermal characteristics measurement of a nanocomposite formed by anatase phase Nps-TiO2 of 5 nm particle size in a polyurethane matrix is reported. The polymeric matrix was obtained through the reaction between the self-condensation of castor oil and diphenylmethane diisocyanate (MDI), while sol-gel technique was used in the synthesis of NPs-TiO2, using titanium (IV)-bis(acetylacetonate) diisopropoxide as precursor. Specific heat (C p ) of the samples was measured by means of the thermal relaxation method and thermal diffusivity (α) was determined with the photoacoustic technique. C p of the nanocomposite increased by 12.98 % due to addition of the NPs, while α decreased by 98.63 %, compared to corresponding values of the polyurethane matrix. With a concentration of 3 wt % of NPs-TiO2 in the matrix, these thermal parameters were found below average values of conventional plastics.

Keywords : thermal conductivity; diffusivity; effusiveness; photoacoustic; nanocompositos; polymer; thermal relaxation.

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