Crystallinity and heats of crystallization of cellulose: A microcalorimetric investigation

Abstract
We have used a sensitive adiabatic microcalorimeter to study cellulose dissolution in its metal complex solvents cadoxen and ferric sodium tartrate (FeTNa). Heats of crystallization of cellulose I and II have thereby been estimated and range from −4.07 kcal/mol to −5.43 kcal/mol. A solvent‐dependent heat of reaction factor has been invoked to explain differences in the heats of crystallization obtained by the two solvents. Conversion of cellulose I to cellulose II is an exothermic process with an enthalpy change of about −6.0 cal/g cellulose. The crystallinities of various cellulose samples have been determined using these thermodynamic data and have been found to be generally consistent with values given by more traditional means.