Compared to CNCH2SO4 prepared via H2SO4 hydrolysis procedure (Tmax = 273 °C), the CNCCr(NO3)3 produced using Cr(NO3)3 hydrolysis system rendered much higher thermal stability (Tmax = 344 °C) than its raw material (Tmax = 295 °C), which can be explained by the fact that less damage happened in crystalline regions of the cellulose matrix benefiting from the milder hydrolysis conditions. In addition, the additional thermal stability is affected by the crystalline structure of cellulose, which increased as a result of the Cr(NO3)3 hydrolysis treatments. Some studies  reported that the high crystallinity nanocellulose could lead to higher thermal stability, but the thermal stability of high crystallinity sulfated CNC was reduced. Similar results have been reported by Mohamed et al.  where the nanocellulose derived from newspaper pulp rendered a lower Tmax value (187.4 °C) than its starting material (346.4 °C) although it had higher crystallinity (90.15%) compared to untreated pulp (82%). In fact, the authors believed that the thermal destruction of cellulose was primarily affected by the presence of sulfate groups from H2SO4, in which the lower thermal stability was correlated to the content of sulfur impurities as well as removal of thermostable minerals during acid hydrolysis of the MCC.