Synthesis and Characterization of Cellulose Acetate From Nata De Coco as Ultrafiltration Membrane

This research was done to obtain membrane raw materials of cellulose acetate derived from Nata de Coco. Nata De Coco (microbial cellulose) with a thickness of 3-5 mm was obtained by fermentation of coconut water waste for six days. Microbial cellulose (CA-1) soaked in 2% NaOH for 24 hours then washed with distilled water and continued with second soaking using 2% acetic acid for 24 hours. Microbial cellulose (CA-2) was treated the same as the CA-1 but using 4% NaOH and acetic acid. Cellulose acetate was obtained through a process of microbial cellulose acetylation and hydrolysis for 20 hours, which predominantly contain cellulose triacetate with an acetyl content of 45.20% for CA-1 and 44.21% for CA-2. FT-IR analysis showed the absorption characteristic of C=O carbonyl group at wave number 1755.2 cm-1 (CA-1) and 1752.25 cm-1 (CA-2) and acetyl C-O group at wave numbers 1232 cm-1 until 1240 cm-1, which showed that synthesis of microbial cellulose into cellulose acetic have occur completely. Cellulose acetate membranes were obtained by dissolving the powder of cellulose acetate using the dichloromethane solvent, continued by immersion precipitation process. Membrane morphology was observed by SEM and the results showed that CA-1 membrane have a pore structure bigger than the CA-2 membrane. Membrane pore size of CA-1 is between 0.009 µm and 0.06 µm, while for CA-2 membrane is between 0.008 µm and 0.04 µm. Base on these characterization results, both synthesis membranes with a thickness of 0.015 mm were characterized as ultrafiltration membranes and have a good characteristic as an ultrafiltration membrane