As suggested by Soom, Hassan, Top, and Kamarudin (2006), the ether group in anhydro glucose units conferred a less crystalline behavior. The less crystallinity of a sample reduced the thermal decomposition of CMSS. Moreover, the per-centage of residue of CMSS also increased as other material was added in derivatization process. The thermal stability of CMSS-acid hydrogel increased slightly where the maximum decomposition temperature is 285.36◦C with 40.30% of the sample remained at the end of analysis. A slight increase in the maximum decomposition temperature could be due to the presence of cross-linkages in CMSS-acid hydrogel.