Thermochemistry of alkalization and etherification of cellulose

In this research, the process of alkalization of cotton cellulose with solutions of sodium hydroxide of different concentrations has been studied. It was found that the enthalpy of cellulose alkalization is exothermic. Moreover, the exothermic enthalpy value of cellulose alkalization with 30-40% NaOH solutions is higher than with 16-20% alkalis. Thus, the cellulose treatment with 30-40% alkalis provides the formation of more reactive alkali cellulose. In addition, the determination of the formation enthalpy of alkali celluloses showed that this thermochemical characteristic is also exothermic, and therefore, the process of cellulose alkalization is energetically favorable. It is most likely that cellulose alkalization is a physicochemical process of forming a molecular adduct of hydrated hydroxide ions with cellulose. A study of the methylation reaction of alkali cellulose with methyl chloride to a degree of substitution of 1.3-1.8 showed that the enthalpy of this reaction is quite exothermic.  This means that methylation reaction is energetically advantageous, and obtaining methylcellulose with a higher degree of substitution is preferable.