Optimation of Alkoxide formed step on Carboxymethyl Kappa Carrageenan synthesis

Abstract

Carboxymethylation of kappa carrageenan with mono-chloroacetic acid as a reactant had been synthesized to produce carboxymethyl kappa carrageenan (CMKC). Carboxymethylation of kappa carrageenan was obtained in two steps. First, alkalization of k-carrageenan with NaOH to create alkoxy k-carrageenan, and optimization of the alkalization step, the optimization had been done include the mass ratio between NaOH and k-carrageenan and alkalization's temperature, second, etherification of alkoxy k-carrageenan with Monochloroacetic acid (MCA) as etherification reactant, to produce CMKC. The optimal condition (2) characterization of the CMKC properties, including the degree of substitution (DS) and FTIR spectrum. The optimal condition was based on the formed degree of substitution(DS) of CMKC. The alkalization of k-carrageenan has been performed on three variations of mass ratio between NaOH: kappa carrageenan flour that dispersed in isopropanol, and then the mass ratio of NaOH: k-carrageenan that has the highest DS was used in the experiment to find the optimal alkalization temperature. To find the optimal temperature, the alkalization was performed at, 40°, 55° and 70°. The CMKC that has the highest DS value was produced when the mass ratio between NaOH mass: kappa carrageenan is 7,2:1, and the temperature of alkalization is 70°C, The DS value that reached when the CMKC synthesis had been done on the optimal alkalization condition is, 0,85.