The Effect of Extrusion Speed on Mechanical Properties of Starch-Based Biocomposite

Plastics are one of the contributors to waste as well as a problem that is difficult to resolve in every country so that a solution is needed to overcome this by synthesizing biocomposite materials. The quality of biocomposite products depends on processing methods. This study discussed the effect of the speed of the extrusion process on the mechanical characteristics and structure of starch-based biocomposite with nanoclay reinforcement. The experimental research method was carried out by using cassava-based biocomposite synthesis with add carrageenan and nanoclay-reinforced with a concentration of 2.5wt% and 5wt%, respectively, with glycerol as a plasticizer. The extruded process was carried out on a single-screw extrusion machine with a speed variation of 0.55, 1.35, and 2.6 g/min and processing temperatures of 120 degrees C. The extrusion product tested using a tensile test and Scanning Electron Microscopy (SEM). The test results show that the speed of extrusion influences the mechanical characteristics and surface of bioplastics. The best tensile strength and strain were 2.48 MPa and 17.91%, respectively, obtained from an extrusion speed of 1.35 g/min. The highest elastic modulus was 21.22 MPa obtained from an extrusion speed of 2.6 g/min. SEM shows no void on the biocomposite surface. For extrusion speed of 0.55 g/min occur uniform fracture, speed of 1.35 g/min show ductile fracture on the edges of biocomposite and speed of 2.6 g/min show small clumps and a little crack.