Comparative Study of Carboxymethyl Cellulose Synthesis from Selected Kenyan Biomass

Abstract

Materials that are of low cost, bio-based and biodegradable are the basis within which today’s industrial technology is trying to accommodate. Cellulose being a low cost polymer is naturally occurring, bio-based, renewable and biodegradable thus its derivatives are incorporated in today’s industrial technology either as transient intermediates or as permanent products. The Isolation of cellulose from Miscanthus sinensis, Eichhornia crassipes and Cyperus papyrus biomasses was done by soda process followed by treatment with acetic acid: hydrogen peroxide mixture. The percentage yield of isolated cellulose from M. sinensis, E. crassipes and C. papyrus was found to be 30.25± 0.25%, 31.64 ± 1.46% and 29.55 ± 0.64% respectively. Characterization of the obtained microcrystalline cellulose revealed presence of functional groups typical of cellulose whereby a peak at 3359.8 cm-1 represented –OH stretching vibration. The peak at wave number 1051.1 cm-1 characteristic of C-O-C group was also observed. Functionalization of Isolated cellulose to obtain carboxymethyl cellulose was done by alkalization followed by Esterification with sodium monochloroacetic acid (SMCA). This was confirmed by presence of CH2COO stretching vibration peak between 1598 – 1605 cm-1. The degree of crystallinity for Miscanthus sinensis was calculated to be 73.93% while the crystal size was calculated to be 1.31 nM. The degree of crystallinity and crystal sizes were calculated to be 71.42% and 0.059 nm for E. crassipes and 46.15% and 0.068 nm for C. papyrus respectively. The yield, degree of substitution and swelling capacity of CMC from M. sinensis, E. crassipes and C. papyrus were found to be dependent on the source of cellulose. This demonstrated that M. sinensis, E. crassipes and C. papyrus are reliable non-conventional sources of cellulose which can be used to synthesize commercial grade CMC products.