Influence of Citrus Fruit Waste Filler on the Physical Properties of Silicone-Based Composites

Silicones have been used as protective coatings due to their resistance to hydrolytic degradation and UV (ultraviolet) degradation. There is a growing problem with managing organic waste, which can be used as fillers in composites. This research demonstrated the use of organic waste from citrus peels, including grapefruit, lime, lemon, and orange peels. Silicone-based composites were prepared by gravity-casting using 2.5, 5, and 10 wt.% waste filler. Samples made from the composite panels were subjected to static tensile, density, hardness, pin-on-disc, and Schopper-Schlobach abrasion tests. The test results showed that lower tensile strength values characterized the composite materials compared to the silicone used as a filler. All materials had greater hardness than the silicone without the addition. At the same time, composites with a mass density of the filler of 2.5 and 5 wt.% showed more excellent abrasion resistance than the silicone used as a matrix. This research showed that the samples containing 2.5 wt.% grapefruit filler had the best mechanical properties and the lowest abrasive wear.