Bio-plastic characteristic from cassava starch modified in variatiations the temperature and pH of gelatinization

The purpose of this study was to investigate the effect of temperature and gelatinization pH on the characteristics of modified cassava starch bio-plastic, to determine the temperature and pH of gelatinization to produce modified cassava starch bio-plastic with the best characteristics. This research uses Factorial Random Block Design. Factor I is a gelatinization temperature consisting of 5 levels i.e. 70; 75; 80; 85 and 90oC. Factor II is a gelatinization pH consisting of 4 levels of 4; 5; 6 and 7. Each treatment combination is grouped into 2 based on the time of the bio-plastics making process, so that there are 40 experimental units. The data obtained were analyzed of variant and continued with the Duncan comparison test. The observed variables include mechanical tests consisting of tensile strength, elongation at break and Modulus Young test, duration of bio- plastic degradation and surface profile and bio-plastic functional groups. The results showed that the temperature and pH of gelatinization and its interaction had a very significant effect on tensile strength, elongation at break, Modulus Young, volume swelling percentage and degradation duration of modified cassava starch. The gelatinization temperature of 75 + 1oC at pH 5 produces the best characteristics of modified cassava starch bio-plastic, i.e. tensile strength 1,657.43 MPa, elongation at break of 10.32%, Modulus Young of 16,060.37 M Pa, percent of volume swelling by 9% and duration of degradation 7.33 days. The profile of the bio-plastic surface of the longitudinal view indicates the presence of dense and regular tissue formed by modified starch polymers with relatively small airspace variations. The cross-profile bio-plastic profile shows a fiber arrangement that forms a regular network or cross linking of a modified cassava starch polymer. Modified cassava starch bio-plastics contain hydroxyl (O-H) based functional groups with hydrogen, alkanet (C- H), aldehydes (C-OH), simple aromatic compounds, carboxyl (C-O), alkenes (C = C) and hydrocarbons –(CH2) n.