The Effect of Paper Mill Sludge Concentration and Composition in Modified Cassava Starch Bioplastic Properties

Abstract

There is widespread recognition of the environmental damage caused by plastics, but its alternative, bioplastics, has lesser tensile and water sorption properties than conventional plastic. This experiment aims to determine the effect of paper mill sludge when mixed into modified cassava starch-based bioplastic when whole and when removed of CaCO3. The bioplastics were made with one control group and 8 other groups containing 10%, 20%, 30% and 40% (w/w) of sludge in total solid content for both whole and fiber-clay sludge. Biodegradation was determined through analyzing CO2 evolution per week via titration as well as through mass loss. Water holding capacity was determined through immersion in distilled water for 2h. Moisture content was determined by heating in an oven at 105°C until stable mass was achieved. Density was determined using a pycnometer. Tensile tests were performed using the UTM at the BMJ paper mill at Karawang, and the sludge was characterized for CaCO3, clay and fiber content. The results could not find significant effects in biodegradability and water holding capacity of the films when given either whole or fiber-clay sludge. What can be concluded, however, is that the control films had the highest elongation at break. Control films also had similar tensile strengths to fiber-clay sludge films, which is higher than films given whole sludge. The fiber-clay sludge films had the highest tensile moduli. In conclusion, sludge is a possible bioplastic filler to improve stiffness.