Processing and characterization of TiO2 filled polymer composites

Abstract

This paper reports on the research dealing with the processing and characterization of TiO 2 filled polymer composites. It also presents the test results in regard to the physical, mechanical and micro-structural characteristics of the epoxy and polypropylene composites filled with micro-sized TiO 2 particles. The effective thermal conductivity of polymer composites with uniformly distributed micro-sized particulates are estimated using a theoretical heat conduction model proposed previously by the authors and the correlation is validated for TiO 2 filled polymers through numerical analysis and experimentation. Some other important thermal characteristics, such as glass transition temperature (T g ) and coefficient of thermal expansion (CTE) of epoxy and polypropylene composites are also estimated. The effects of TiO 2 content on these properties of epoxy and polypropylene have been studied experimentally. The estimation of effective thermal conductivity of the composites using finite element method (FEM) and the proposed theoretical model is done and the results are validated by corresponding experimental results. The findings of this research suggest that incorporation of TiO 2 into epoxy and polypropylene leads to substantial improvement in thermal conductivity and glass transition temperature of the resins. At the same time, TiO 2 helps in lowering the coefficient of thermal expansion of such composites. This work further shows that the FEM serves as a good predictive tool for assessment of thermal conductivity of these composites. The theoretical correlation proposed in this work can serve as a very good empirical model for spherical inclusions to estimate the effective thermal conductivity of the composites within the percolation limit. With light weight and improved heat conduction capability, the TiO 2 filled polymer composites can be used for applications such as electronic packaging, encapsulations, communication devices, thermal interface material, printed circuit board substrates etc.