The Effect of Mass Ratio between NaOH to k-Carrageenan and Alkalization Temperature on Carboxymethyl k-Carrageenan Synthesis

This article presents a study on the effect of the mass ratio between NaOH to k-carrageenan variation and alkalization temperature variation, on the synthesis of carboxymethyl k-carrageenan (CMKC). This research was done in two-step (1) Alkalization of k-carrageenan with NaOH as reactant on several mass ratios between NaOH and k-carrageenan, and optimization of the alkalization temperature, followed by etherification of alkoxy k-carrageenan with trichloroacetic acid (TCA) as etherification reactant (2) characterization of the CMKC properties including the degree of substitution (DS) and FTIR spectrum. The results showed that CMKC was synthesized, indicated by the appearance of carbonyl absorption peaks in the FTIR spectrum of CMKC, around 1650 and 1410 cm^-1. The mass ratio between NaOH and k-carrageenan affected to the DS value of CMKC that was synthesized, the mass ratio between NaOH and k-carrageenan that had the highest DS value, was 7.2:1 The alkalization temperature also influenced the DS value of CMKC, the optimal alkalization temperature is 40 ° C.