Poly(trimethylene terephthalate) (PTT)/poly(butylene terephthalate) (PBT) blend and its ternary systems reinforced by carbon nanotubes (CNTs) were prepared by melt-mixing.The effect of CNTs on the transesterification between PTT and PBT was then studied through nuclear magnetic resonance spectroscopy (NMR).The possible mechanisms were then discussed preliminarily according to the observations by transmission electron microscopy (TEM) scanning electron microscopy (TEM) and sedimentation experiments

as well as the results from other measurements such as rheology and dynamical thermal mechanical analysis (DTMA).The as-obtained PTT/PBT is a typical thermodynamical miscible blend system and

small amounts of tetrabutyl orthotitanate (Ti(OBu)4) can promote ester inter-change reactions between PTT and PBT components effectively.The addition of CNTs during melt mixing can further facilitate transesterification in the systems

resulting in evident decrease of the number-average length (LB and LT) of PTT-PBT copolymers and increase of the degree of randomness (B) of systems.This indicates that the CNTs can catalyze or even participate in the ester inter-chain reactions in the ternary systems.Such an effect

however

shows high dependence on the CNT loadings.With increasing CNTs loadings

the transesterification degree (Y) of ternary systems reduces gradually.