3.2. Impact strength and toughening mechanism
The effect of TBT concentration on the impact strength of PLA/
PBAT blends is illustrated inFig. 4, and the impact strength of pure
PLA is also presented for comparison. The impact strength is increased from 3 kJ/m
2
for pure PLA to 5 kJ/m
2
for the uncompatibilized PLA/PBAT blends. The toughness of blends is improved
prodigiously at 0.2 wt.% TBT and below, and the impact strength
of blends containing 0.2 wt.% TBT is increased by 76% as compared to pure PLA. However, the toughness of blends has almost no
improvement with the further increasing TBT loading level. This
result is in good agreement with that of literature [11]. Zhang
et al.[11] observed that the impact strength of PLA/PBAT blends
suddenly increased at 1 wt.% of T-GMA and then trended to be saturated. However, with further addition of T-GMA beyond optimum
amount range, the impact strength gradually decreased