Tetrabutyl titanate has been selected as transesterification catalyst of poly(lactic acid) (PLA) and polycarbonate (PC) to investigate transesterification mechanism between poly(lactic acid) (PLA) and polycarbonate (PC) and the influence of transesterification reaction on the morphology of blends with different compositions.It is found that the transesterification reaction time

the fraction of reacted PC

the composition of polycarbonate in copolymer

the weight and mole number of PC-co-PLA copolymer increase substantially with the increasing of the composition of poly(lactic acid) in the blends no matter the catalyst is added or not.The difference in the amount of the reacted PC between 70/30 and 30/70 blends increases further with the addition of catalyst due to the easier alignment of PLA segments in copolymers along the interface when poly(lactic acid) is the continuous phase as compared with polycarbonate to be the continuous phase.Moreover

the interfacial reaction mechanism in PLA/PC 30/70 blend is found to be changed with the addition of catalyst since the dominated factor that influences the ester exchange reaction has changed.Furthermore

the domain size of dispersed phase decreases due to the promotion of transesterification by tetrabutyl titanate.Especially

larger mole number of copolymer in blends with PLA as continuous phase is produced when catalyst is added

which causes a more evident decrease in domain size in blends with PLA as continuous phase as compared to that in blends with PC as continuous phase.