Thermal Stability of Compatibilised Natural Rubber/ Chitosan Blends

Abstract

The thermal degradation behavior of Natural Rubber /Chitosan (NR/CS) blends compatibilised with maleic anhydride (MA) was studied by thermogravimetric analysis (TGA). The TGA shows that the MA modified blends are more stable than the pure blends. MA acts as a reactive compatibiliser in NR/CS blends. MA grafted NR chain is highly reactive towards the functional group on the chitosan moiety, and when pressing at elevated temperature interaction develops between the maleic anhydride treated NR and chitosan. Better adhesion between the two phases with the incorporation of MA is achieved which results in an enhancement in the thermal stability. The activation energy of degradation was analyzed using the Horowitz-Metzger equation. The compatibilisation resulted in an increase in the activation energy. The glass transition temperatures of NR/CS blends were increased substantially by the addition of MA and this indicates better compatibility between the two phases. The morphology of the compatibilised blends was studied by scanning electron microscopy and it shows a continuous morphology. The water absorbability of blends decreases with the addition of compatibilizer in the blend.