The loss factor (tand) of pure PLA and its blends are showed in
Fig. 7. Two peaks are observed for pure PLA, one at ca. 5C which ascribes tobrelaxation of PLA and one at ca. 70C which contributes to the glass transition temperature of PLA. By contrast, theb
relaxation peaks disappear and two weak peaks are observed for
all blends. The weak peaks at ca.30Cto20C and at 110C
attribute to theTgof PBAT and cold crystallization of PLA, respectively. A sharp peak at ca. 60–72C belongs to theTgof PLA. The
occurrence of twoTginfers that PLA and PBAT used in our works
is incompatible. Notably, the Tg regardless of PBAT or PLA tends
to increase with the TBT concentration. It suggests that the PLA
chain mobility is hindered by the strong interaction which generated through transesterification between PLA and PBAT.