The influence of TiO2 and ZnO on thermal stability of PET/PBS blends were graphically shown in Fig. 6. The
single stage in the thermal degradation occurred for the case of PET/PBS blends with TiO2 at around 370-450 oC.
The decomposition temperature of PET/PBS blend is 425 oC, and that of PET/PBS blends with TiO2 1% and 2% are
425oC and 429 oC, respectively. This indicated that the addition of TiO2 2% wt could increase heat stability for
polymer blends due to high thermal stability of TiO2. It could absorb heat that make polymer blends withstand heat
up to higher temperature. However, addition of TiO2 at 1% wt could not improve heat stability of PET/PBS blends.
Considering the effect of ZnO in Fig. 6, thermogravimetric diagram was performed for the PET/PBS blends with
ZnO 1% and 2% wt which resulted in two stages decomposition. The first stage from 340-360°C was due to the
degradation of 10% of PBS. The second stage was related to the degradation of PET at the range of 360-440 oC.
PET/PBS blends with higher amount of 2% ZnO showed the onset temperature for thermal degradation at lower
temperature. ZnO would be able to form free oxygen and oxygen vacancies in the lattice induced by thermal energy
and took place in the PBS degradation process.