The Effect Analysis of ZnO Variations on Corn Starch and Cellulose Biocomposites toward Impact Strength

Abstract

Biocomposites made from renewable resources make biocomposites a more viable and promising alternative for the manufacture of metal replacement materials. The use of polyester resin as a matrix in composites does have good mechanical properties. However, it needs development to improve the mechanical properties better, namely by adding corn starch to help the polyester resin matrix. The addition of ZnO and cellulose to strengthen the mechanical properties of the biocomposite. This research was conducted using an experimental method, namely by varying the percentage of 100% Polyester Resin, 2.5% ZnO, 5% ZnO, and 7.5% ZnO to determine the difference in the impact value of the biocomposite. From the impact test results, the specimen with the best mechanical properties will be continued with X-Ray Diffraction testing, to determine the crystallinity index and crystal size. Based on data analysis and discussion, the average impact value of biocomposite 100% Polyester Resin, 2.5% ZnO, 5% ZnO, 7.5% ZnO respectively 0.0139 J/mm2 0.0188 J/mm2 0.0241 J/mm2 0.0168 J/mm2. The best impact value was obtained on biocomposite specimens with a percentage of 5% ZnO. The average impact value obtained is 0.0241 J/mm2. The results of the calculation of the crystallinity index on the specimens with a percentage of 2.5% ZnO, 5% ZnO, and 7.5% ZnO respectively 70.58%, 73.43%, 81.16%, with a crystal size of 28.53 nm, 42.80 nm, 52.21 nm. It can be seen that as the percentage of ZnO increases, the crystallinity index and crystal size increase.