Karakterisasi Variasi Biokomposit [CaCO3 : Bioplastik /Corn Starch] Terhadap Sifat Mekanis dan Mikrostruktur

Abstract

ABSTRACT

The presence limestone can be used as biomaterial for bone support. CaCO₃ as matrix biocomposite and bioplastic as reinforce. This work aimed to study the effect of suspension CaCO₃ and corn starch as bioplastic in mechanical properties such as tensile strength, flexural strength, shrinkage and also microstructure. The ratio composition of suspension CaCO₃ : Corn Starch namely is 20:80 (w/w)%, 30:70 (w/w)%, 40:60 (w/w)%, 50:50 (w/w)% . 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 20:80 (w/w)%, specimen B code for composition 30:70 (w/w)%, specimen C code for composition 40:60 (w/w)%, and specimen code D for composition 50:50 (w/w)%. Based on the results of the shrinkage measurement, it showed that specimen B had the highest average shrinkage value of 180.011% for the tensile test specimen, and 160.022% for the flexural test specimen. The results of the tensile test and flexural test also showed that specimen B had the highest average value, namely the ultimate tensile strength of 0.110.015 MPa and flexural strength of 0.020.012 MPa. Meanwhile, from the microstructure test, namely SEM-EDX, the results were in the form of a spheroid-shaped specimen morphology and the dominant elements contained in the specimen were C, N, O, and Ca.