SYNTHESIS OF ADDITIVE OXIDANT FOR HIGH DENSITY POLYETHYLENE (HDPE) AND ITS BIODEGRADATION

• Main Author: Rasnyanti M Aras, Neny
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34170
• Institution: Institut Teknologi Bandung

An oxidant additive is one type of additive used for oxo-biodegradable polymers. This additive is prepared by reaction multivalent transition metals and fatty acids to accelerate the degradation process of polymers by providing a thermal treatment or irradiation with light. This study focused on the synthesis of manganese stearate as an additive for application in High Density Polyethylene (HDPE), and the influence of manganese stearate on the characteristics of HDPE including their biodegradability. Manganese stearate was synthesized by the reaction of stearic acid with sodium hydroxide, and sodium stearate formed was reacted with manganese chloride tetrahydrate to form manganese stearate with a melting point of 100-110 °C. Based on the FTIR spectrum showed absorption peaks at wave number around 1560 cm-1 which is an asymmetric vibrations of CO functional group that binds to the manganese. The films of oxo-biodegradable polymer were prepared by blending HDPE and manganese stearate additives at various concentrations with using the polymer melting method, followed by UV light irradiation or heating at a temperature of 50?C and 70?C for 10 days. The characterizations of the oxo-biodegradable polymers were carried out by analysis the biodegradability (% weight loss), the functional groups (FTIR), thermal properties (TGA/DSC), mechanical properties (Tensile tester), surface properties (SEM), as well as analysis of the biodegradation test by using activated sludge. The addition of manganese stearate as the oxidant additive in HDPE at various concentrations, and followed by irradiation with UV light for up to 10 days did not show significant changes in the intensity of the absorption peak at the wave number of 1700-1800 cm-1 which is a carbonyl functional group, while those followed by heating at 50?C and 70?C for 10 days showed the increase of the absorption peak intensity of carbonyl groups at 1700-1800 cm-1, and the increase of the heating temperature and the concentration of manganese stearate added to HDPE, the intensity of the carbonyl group absorption increased. These results indicate that the additive of manganese stearate is more active in oxidizing polymer by heating compared to irradiation with UV light. Based on the analysis of the mechanical properties, the addition of manganese stearate in HDPE followed by irradiation with UV light can decrease the mechanical properties of HDPE, although this effect is lower than that followed by heating at a temperature 50?C and 70?C for 10 days, and the higher concentration of manganese stearate is added to HDPE, the value of Young modulus of polymers increases or the polymer becomes more rigid. Results of biodegradation by microorganisms from activated sludge showed that the percentage weight loss of polymers increase with the increasing incubation time and the concentration of manganese stearate in HDPE. Biodegradability of HDPE with the addition of manganese stearate and followed by heating at a higher temperature was better observed than that followed by irradiation with UV light. The highest percentage weight loss was obtained at the polymer with concentration of 0.2% manganese stearate, and followed by thermal treatment at a temperature of 70 °C and the incubation time for 45 days in the activated sludge.