Pengaruh Variasi Biokomposit (CaCO3: Tepung Jagung) Terhadap Nilai Penyusutan, Kekuatan Tarik, Kekuatan Tekuk, dan Mikrostruktur

Abstract

Limestone can be used in the world of health, namely as a biomaterial for the manufacture of bone support plates. One of the artificial biomaterials used for bone support plates is biocomposite. Before applying biocomposites for bone support plates, it is necessary to know the right composition between bioplastics and bioceramics so that the bone support plates have good mechanical properties,, therefore several tests were carried out such as shrinkage, tensile tests, flexural tests, and scanning electron microscopy with energy dispersive X-ray spectroscopy to determine the microstructure and elements involved. contained in the biocomposite. In this study using 4 variations of the mass ratio of suspension CaCO3 : Corn Starch as biocomposite, suspension CaCO3 as matrix and Corn starch as bioplastic. The dimensions of the tensile test specimen are in accordance with the ASTM D638 type 4 standard, and the dimensions of the flexural test specimen are in accordance with the ASTM D790 standard. Samples are given codes such as specimen A code for composition of suspension CaCO3 20:80 corn starch (weight/weight)%, specimen B code for composition suspension CaCO3 30:70 corn starch (weight/weight)%, specimen C code for composition suspension CaCO3 40:60 cornstarch (weight/weight)%, and specimen code D for composition suspension CaCO3 50:50 corn starch (weight/weight) %. Based on the results of the shrinkage measurement, it showed that specimen B had the highest average shrinkage value of 18 ± 0,011 for the shrinkage tensile test specimen, and 16 ± 0.022 for the shrinkage flexural test specimen. The results of the tensile test and flexural test also showed that specimen B had the highest average tensile test value, namely the ultimate tensile strength of 0.11 ± 0.015 MPa and flexural strength of 0.02 ± 0.012 MPa. Meanwhile, from the microstructure characterization use scanning electron microscopy with energy dispersive X-ray spectroscopy, the results were in the form of a spheroidshaped specimen morphology and the dominant elements contained in the specimen microstructure were element C is 35.38% mass, element N is 11.74% mass, element O is 50.13%mass and element Ca is 2.74% mass in K atom shell.