The thermal stability of natural melanins from bovine eyes, black human hair and the hard core of banana peel, synthetic melanins obtained enzymatically or by autoxidation of various precursors, and chemically modified synthetic mclanins was studied by DSC and TG analysis. It was shown that the resistance of melanins to thermal degradation depends on their origin. Synthetic melanins were found to be more stable to thermal decomposition than natural melanins. Methylation of melanins caused a significant increase in thermal stability. The DSC curves of melanins reveal typical relaxation phenomena in the temperature range 293-413 K.
It is generally believed that melanins