A Preliminary Investigation on the Thermal Behavior of Polysaccharides-Modified Casein

The effective use of natural casein-based adhesives requires the reduction of shrinkage phenomena associated with the evaporation of water, which is largely used for preparation. After the procedure optimization of a casein natural glue by aid of an alkaline solution, it was modified by the addition of two different sugars with long and short chains—chitosan and dextrose, respectively—at different weight concentration levels to absorb and retain water. The thermal decomposition and degradation kinetics of prepared sugar-based casein glues have been analyzed by performing thermogravimetric TGA characterization at different heating rates. Experimental results and the evaluation of thermal degradation activation energy by Kissinger analysis evidenced that the chitosan and dextrose could be efficient and sustainable additives to control and mitigate the degradation mechanisms of casein glues. Further, vertical flammability tests (UL 94 standards) on the sugar-modified casein materials with the highest sugar content confirmed the positive effect of chitosan and dextrose addition under flame exposure too.