Figure 6 shows the results for the composites with 3 wt% of the four different clay types. It can be seen that the addition of all clay fillers leads to a slight improvement of the thermal stability of the PBAT matrix.
ascribed the enhancement in thermal stability of PBAT reinforced with natural and functionalized MMT to a shielding effect of the clay layer in well-dispersed samples as well as to the strong interaction between clay and PBAT molecules in general.
in our case, the lower increase of thermal stability for natural bentonite compared to the other clay fillers could be due to the poor bonding of bentonite to the PBAT matrix, which is observed in SEM images (Fig. 2).