The Effect of Increasing Chitosan on the Characteristics of Bioplastic From Starch Talas (Colocasia Esculenta) using Plasticizer Sorbitol

The aims of this research to determine the profile of starch gelatinization, bioplastic and the effect of increasing chitosan and sorbitol to the properties of tensile strength and elongation of break bioplastic. Preparation of bioplastics was used by casting method, that is 30% w/v solution of starch mixed with chitosan solution (0.5 w/v; 1 w/v; 1.5 w/v; 2 w/v; and 2.5 w/v) and plasticizer sorbitol (10 % w/w; 20 % w/w; 30 % w/w; 40 % w/w and 50 % w/w) were heated using a hotplate magnetic stirrer at 750C. The results of Rapid Visco Analyzer (RVA) obtained by starch and bioplastic gelatinization temperature of 72.94°C; 77.72°C with peak viscosity 6632 cP and 3476 cP. Analysis of Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) obtained the change a functional group of bioplastic OH at wave number 3765 cm-1 and uneven chitosan distribution, and there is still an empty fraction. The addition of chitosan and sorbitol had an effect on tensile strength and elongation at break, tensile strength and elongation at break the highest of 8.36 MPa and 22.06% in starch composition 30%, 2.5 w/v chitosan and sorbitol 30% w/w.