Effect of particle size and weight fraction on the flexural strength and failure mode of TiO2 particles reinforced epoxy

Effect of inclusions size and weight fraction on flexural strength and failure mode of composite containing SC-15 epoxy resin and TiO2 particles has been studied in this investigation. The sizes of particles varied from macro (0.02 mm) to nano (5 nm) scale, and these particles were infused into the part-A of SC-15 through sonic cavitations and then mixed with part-B of SC-15 by using a high speed mechanical agitator. Three-point bending tests were performed on unfilled, 0.5 wt.%, 1.0 wt.% and 1.5 wt.% particles filled SC-15 epoxy to identify the loading effect on mechanical properties of the composites. Results show that 1.0 wt.% nanoparticles reinforced epoxy exhibit the highest mechanical performance. Higher than 1.0%, strength of composite decreased because of poor dispersion. Experimental results also shown that micro-sized particles have little effect on strength of epoxy at such low loading, and strength of composite increased as the size of particles decreased to nano scale. However, degradation in strength was found in 5 nm TiO2/epoxy system due to agglomeration. (C) 2010 Elsevier B.V. All rights reserved.