Optimized carboxymethyl cellulose preparation from cocoa pod husks by surface response methodology

This study investigates the synthesis of carboxymethylcellulose (CMC) from cocoa pod husk (CPH) using optimized Williamson etherification process. Response surface methodology (RSM) was used to model the independent variables such as reaction time, concentration of NaOH and amount of monochloroacetic acid (MCA) versus the degree of substitution (DS). The optimum results of independent factors were 20% NaOH, and 3.5 g monochloroacetic acid (MCA) with reaction time of 120 min while DS at that condition was 1.096 at a significant level of P<0.0001 and F-value of 15.78. The FTIR spectra revealed the functional group modification of native cellulose to CMC, This is verified from the spectrum transmitting 1409.49 cm-1 and 1640.05 cm-1 indicating ether and carboxyl functional group consecutively. The results of XRD analysis showed that crystallinity of cellulose had decreased in CMC while SEM/EDS showed the elongated long fibres in cellulose while the fibrils in CMC is short and rough. The optimum percentage yield obtained shows that cocoa pods can be a good alternative for the production of large scale CMC. Keywords: Cocoa pod husk, carboxymethyl cellulose, cellulose, Response Surface Methodology, degree of substitution, characterization.