Sintesis Selulosa Asetat Berbahan Dasar Tongkol Jagung sebagai Material Membran dengan Variasi Temperatur Asetilasi

Abstract

Corncob is classified as a type of agricultural lignocellulosic waste containing cellulose, hemicellulose, and lignin. Cellulose is an important component in corncobs which can be isolated through delignification process. The isolated cellulose has a water content of 4,46% and FTIR analysis shows the absorption of O-H stretching, C-H stretching, O-H bending, C-H bending, and C-O stretching groups. Cellulose can be modified into cellulose acetate through the acetylation process. Cellulose acetate synthesis was carried out at various temperatures of 40°C, 50°C, 70°C, and 90°C. The characterization of cellulose acetate was carried out by testing the acetyl content and degree of substitution, molecular weight, solubility percent, and functional groups by FTIR. The acetyl content and degree of subtitution increased with increasing acetylation temperature. Synthesis of acetyl cellulose acetate respectively was 27,73; 32,28; 38,77; 42,88% with a degree of substitution of 1,433; 1,776; 2,351; and 2,780. Based on the acetyl content and the degree of subtitution, cellulose acetate at acetylation temperature of 40 C and 50 is classified as cellulose monoacetate, while cellulose acetate at 70 C and 90 C acetylation temperature is classified as cellulose diacetate. The molecular weight of cellulose acetate decreased at the acetylation temperature of 90°C. The solubility percent of cellulose acetate shows that cellulose diacetate has greater solubility in acetone than cellulose monoacetate. Structural analysis of synthesized cellulose acetate showed the absorption of O-H stretching, C=O ester, C-O acetyl, C-O stretching, C-H stretching, and C-H bending groups. Cellulose acetate membrane was made with the composition of 20% CA, 61% DMSO, 15% acetone, and 4% DMP with the addition of 2% SDS. The resulting membrane from the 1:1 (w/w) commercial/synthetic CA mixture had density and swelling degrees of 0,4233 g/cm3 and 336,851% and flux water and permeability coefficients of 36,2807 L/m2 hour and 5,8105 L/m2 .hour.bar.