MECHANICAL PROPERTIES OF EPOXY MATRIX COMPOSITES REINFORCED WITH GREEN SILICA PARTICLES

Recent developments indicate that a significant improvement in mechanical properties of thermosetting polymers may be obtained by using submicron inorganic fillers. Submicron silica particles with average particle size of 0.5 gm was extracted from rice husk ash (RHA) by sol-gel process and used as reinforcement for epoxy resin. Composites were developed by incorporating the silica particles in the weight fractions of 0.5, 1, 2, 3, 4 and 6wt% in an epoxy resin. Mechanical properties (tensile, flexural, hardness) of the developed composite was investigated. Silica particles incorporation shows beneficiary effect on the modulus of elasticity, flexural modulus and hardness with threshold value experienced at 2 wt%., However tensile strength and flexural strength where found to decrease upon silica addition, the flexural strength values being somewhat higher than their tensile counterparts. SEM images of the specimens revealed the manner of silica dispersion in the matrix. Silica particles extracted from rice husk ash can be used as good reinforcing filler for epoxy resin; However, a compromise must be reached in deciding the content of rice husk silica to be incorporated so as not to sacrifice too much of its tensile and flexural strength.