Abstract:The melting process of NC was examed by using MDSC technique,microscope carrier method and incorporation with the solid reaction cell/RSFT-IR. The experimental results show that the endothermic process in the MDSC curve is invertible. It is caused by the phase change from solid to liquid of the mixture of initial NC and partly decomposed products in condensed phase. The values of the melting point,melting enthalpy ( ΔHm),melting entropy (ΔSm),and the enthalpy of decomposition (ΔHdec) and the heat-temperature quotient (ΔSdec) obtained by the MDSC curve of NC at heating rate of 10K·min-1 are 476.84K,205.6J·g-1,0.4312J·g-1·K-1,-2475.0J·g-1,-5.242J·g-1·K-1,respectively. The MDSC analysis results of NC with different nitrogen contents show that with increase of nitrogen content in NC,the absolute values of ΔHm,ΔSm,ΔHdec and ΔSdec increase.