Bioplastic material has emerged as one solution to the environmental problem caused by commercial plastic. Several raw materials have been used for bioplastic production, such as cassava, potato, and sago starch. This research focused on studying the effect of fillers and plasticizers variation to tensile strength and its morphology by using sago starch/citric acid-based bioplastic. The comparison of sorbitol and glycerol role as the plasticizer and microcrystalline cellulose and carboxymethyl cellulose as fillers were observed. This study was conducted by mixed and heated sago starch and fillers together. Then, citric acid and plasticizers were employed in the mixture solution. Next, the mixture was heated for 24 h then molded. The concentration of fillers, plasticizers, and citric acid were used as an independent variable which the interaction among them were investigated using response surface methodology (RSM) based on Central Composite Design (CCD). ASTM D822 evaluated tensile strength, and the morphological analysis was observed by using scanning electron microscopy (SEM). The results showed that the highest tensile strengths were 8.23 MPa for the glycerol and CMC process and 15.84 MPa for the sorbitol and MCC process. It was found that sorbitol and microcrystalline cellulose (MCC) increased the value of tensile strength twofold more than other fillers and plasticizers. As for the response surface method, the results describe the significant interaction between plasticizer and filler. It showed the tendency of increasing the concentration of fillers and citric acid decreased the tensile strength.

Bioplastic or biodegradable plastic is one of alternative replacement to conventional plastic that has the potential to harmful to the environment. One of the raw material that has the potential to be made into bioplastic is sago starch because it has ability to degraded. The general purpose of this research is to determine the characteristics of sago-based bioplastic by modified the citric acid, microcrystalline cellulose filler, plasticizer sorbitol and glycerol. The synthesis method is casting of starch, water, filler Micro Cristalline Cellulose (MCC) with varying plasticizer sorbitol and glycerol with composition of filler is (15-25 % w/w), composition of plasticizer (25– 35 % w/w), and composition citric acid (3-9 % w/w). The results showed that the treatment with the addition of MCC fillers, plasticizers, and citric acid are contributed to the mechanical properties produced. In the best process conditions (20% w/w MCC filler, plasticizer sorbitol 30% w/w with citric acid 0.95% w/w) give result Tensile strength 15.84 MPa, Elongation 9.32%, Young's Modulus 171.2 MPa, Biodegradation 51.65%, and wavelength absorption 1722.51 cm-1