The effect of isopropyl alcohol- 2-butanol mixed solvent on degree of substitution of carboxymethyl cellulose from water hyacinth (Eichhornia crassipes) cellulose

Carboxymethyl cellulose (CMC) is one of the most important cellulose derivatives in various industrial uses. Non-wood cellulose resources have been utilized recently as raw material for production of CMC. Water hyacinth has rapid growth rate and contains relatively high cellulose content, which makes it potential of becoming non-wood cellulose source for the CMC synthesis process. In the present study, synthesis of CMC was conducted by using water hyacinth cellulose as raw material and employing mixtures of two solvent as a reaction medium, those are isopropyl alcohol and 2-butanol with NaOH concentration of 10%-weight. Influence of reaction medium composition on the degree of substitution (DS) was investigated. This mixed solvent which is used as reaction medium with various composition, that is 20:80, 50:50, and 80:20, will provide various polarities that affect the crystallinity of alkali cellulose. CMC production involves two steps, which are alkalization and carboxymethylation process using NaOH solution for 1 h at room temperature and sodium monochloroacetate as etherification substance conducted for 3.5 hours at 55^oC, respectively. The observed characteristics of CMC product include morphology, functional groups, and the DS. In this research, the maximum DS value of water hyacinth CMC was achieved at reaction medium composition of 50:50. This result is in agreement with crystallinity degree of alkali cellulose that was calculated from x-ray diffractogram.