The Effect of Calcium Carbonate Addition to Mechanical Properties of Bioplastic Made from Cassava Starch with Glycerol as Plasticizer

Abstract

Bioplastic is an environmentally friendly type of plastic that is easily degradable by air temperature, humidity, and microorganism. Cassava starch is widely used as the main ingredient in the making of bioplastics. The use of cassava starch for making bioplastics has plenty of potential because cassava is widely cultivated throughout Indonesia. This study aims to obtain the optimal value of adding calcium carbonate as a reinforcer to bioplastics made using cassava starch with glycerol plasticizer. Bioplastics were made by blending and cast printing methods. The stage of making bioplastics begins with the extraction of cassava into cassava starch as a base for making bioplastics. Then, calcium carbonate was added. Addition of calcium carbonate was done with variations (0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0%). Characteristics of mechanical properties were studied namely tensile and elongation tests. The tensile test show that the best tensile strength was obtained at 0.4% calcium carbonate (22.88 ± 1.46 MPa). While the addition of 0.5 to 1.0% decreased the tensile strength. The best elongation value was obtained by the addition of 0.8% calcium carbonate (27.57 ± 0.14 %).