Fig. 5

TGA analysis of A PLA, C PLA–chitosan, and E PLA–chitosan–HA nanoparticles and DTG analysis of B PLA, D PLA–chitosan, and F PLA–chitosan–HA nanoparticles. The TGA curve shows the weight changes of the sample during increasing temperature or time. The DTG curve is the first derivative of the TGA curve and relates the rate of weight change to time or temperature. The shape of the DTG curve shows the peak points and the maximum rate of weight change, which can accurately identify the starting and ending points of material decomposition and thermal reactions