The thermal stability and decomposition of in-situ crosslinked nanocellulose whiskers – poly(methyl vinyl ether-co-maleic acid) – polyethylene glycol formulations (PMVEMA-PEG), (25%, 50%, and 75% whiskers) – were investigated using thermal gravimetric analysis (TGA) methods. The thermal degradation behavior of the films varied according to the percent cellulose whiskers in each formulation. The presence of cellulose whiskers increased the thermal stability of the PMVEMA-PEG matrix. Application: It is possible to develop novel material properties by cross-linking cellulose whiskers in which the final physical properties are derived from the cross-linking reagents and cross-linking density. This study examines the thermal properties of cross-linking sulfuric acid derived cellulose whiskers with PMVEMA-PEG, which will be a key property as these tunable hydrogels are utilized for value-added packaging applications.