PREPARATION AND CHARACTERIZATION OF CELLULOSE ACETATE MEMBRANE OF RICE STRAW PULP

• Main Author: Ode Ahmad (NIM 205 02 018), La
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8454
• Institution: Institut Teknologi Bandung

Abstract : <br /> <br /> <br /> Raw materials for membrane preparation which are often used is cellulose acetate. Cellulose is the main component of both wood and non wood. At present, the usage of wood is going to be limited. Therefore, it requires to look for other sources of cellulose which are abundant and cheap. The purpose of this research is to look for the alternatives of membrane raw materials by exploring Indonesia natural resources. Rice straw is one of non wood cellulose which can be used to prepare cellulose acetate (CA). In this work, cellulose has been acetylated with acetic anhydride and sulfuric acid catalyst for 20 hours at 40 C and hydrolized with acetic acid 67% for 20 hours. The CA showed an acetyl content of 38.41%. Analysis of FTIR showed typical band of acetyl group at 1236 cm-1 and the obtained CA has a relative molecular mass of 2.74 x 104. Glass transition temperature of both rice straw CA and commercial CA obtained by DTA was 194.5 C. XRD analysis indicated that rice straw cellulose has a degree of crystallinity of 41.4% while rice straw CA and commercial CA have degrees of crystallinity of 15.1% and 13.6% respectively. CA membranes were prepared by phase inversion method with the composition: 14% (w/w) CA, 81% (w/w) acetone, and 5% (w/w) formamide. Water flux at 2 atm was 7.44 +/- 0.17 L/m2.h for the rice straw CA membranes and 3.57 +/- 0.18 L/m2.h for the membranes of commercial CA. MWCO was 5.13 x 104 for the rice straw membranes and 2.24 x 104 for commercial ones. Modulus of elasticity of rice straw CA membranes was 9.03 x 107 N/m2 while commercial CA membranes was 1.23 x 108 N/m2. Bursting strength of rice straw CA membranes and commercial SA membranes were 1.2 x 104 N/m2 and 4.2 x 104 N/m2 respectively. SEM photographs showed that commercial CA membranes have smaller pore area than rice straw CA membranes and hence, water could not permeate during the application of membranes for turbid water clarification. On the other hand, rice straw CA membranes could give a flux of 3.57 +/- 0.18 L/m2.h and a rejection coefficient higher than 96%. <br />