NATURAL ORGANIC-INORGANIC MATERIAL UTILIZED AS A FILLER IN POLYMER SYSTEMS

The aim of this work is to evaluate an influence of organic-inorganic natural filler on the selected parameters of epoxy resin composite systems. The natural filler investigated has a character of agricultural waste and is characterized by a high silicon dioxide content. Silicon is absorbed by a plant in the form of a silicic acid colloidal solution and as a consequence of biological processes silica particles of nanometre or submicron dimensions are created in the plant. These particles form a compact barrier in grain husks and protect grains from different environmental influences. The filler of 1 to 100 mu m particle size was prepared by grinding and it was subsequently added to the commercially produced epoxy resins in order to evaluate the influence of the filler on the selected mechanical parameters. An impact of the filler in composite systems was evaluated in the range from 0.1 phr to 50 phr. It was found that adhesion between filler particles and the polymer matrices is good and so was the homogeneity of samples studied by scanning electron microscopy and EDX analysis. The cured and filled epoxy systems were evaluated in order to find out the influence of the filler on the tribological behaviour. The wear rate (the weight loss of the sample) after a total sliding distance of 20,000 cycles was measured, as well as the influence of the filler on micro hardness and the Young's modulus. The wear rate reduction depends on the amount of the filler and can reach 70 %.