Preparasi dan Karakterisasi Biopolimer Berbasis Selulosa Bakteri dengan Karboksimetil Selulosa Secara Insitu

Abstract

A research study on the preparation and characterization of bacterial cellulose-based biopolymers from green tea kombucha with in-situ addition of carboxymethyl cellulose has been conducted. Bacterial cellulose was produced by preparing a 500 ml solution of green tea with the addition of 50 g of granulated sugar, 50 ml of starter culture, and in-situ addition of carboxymethyl cellulose as an additive at varying concentrations of 0.5%, 1%, 1.5%, and 2%. The fermentation process was carried out for 14 days. The resulting bacterial cellulose was purified using 0.5N hot NaOH and distilled water. The characterization of the biopolymer included thickness measurement, yield measurement, and characterization using FTIR, XRD, SEM, Tensile Strength Testing, and TGA. The characterization results of the biopolymer indicated that the thickness and yield values increased with the addition of carboxymethyl cellulose at specific concentrations compared to bacterial cellulose without carboxymethyl cellulose. The best results were obtained from the kombucha tea bacterial cellulose with the addition of 0.5% carboxymethyl cellulose, with a thickness value of 1.72 mm and a yield of 37%. The FTIR spectrum showed the presence of functional groups such as OH, C-H, C=O, CH2, and C-O-C in the resulting biopolymer. XRD diffractograms indicated a degree of crystallinity of 59.2%. SEM results revealed that carboxymethyl cellulose coated the nanofiber network of cellulose uniformly and densely. It exhibited a tensile strength of 2.73 MPa, elongation of 51.7%, and an elastic modulus of 9.15 MPa. Thermal analysis results showed a two-stage decomposition process The first decomposition occurred at a temperature of 350.77°C, while the second decomposition occurred at 564.45°C with a total mass loss of 80.10%.