Polyethylene terephthalate(PET)/polycaprolactone(PCL) segmented copolymers with different hard segment contents and a blend of two of them were studied by using DSC

WAXS

TEM and IR techniques and dynamic mechanical

stress-strain and isothermal crystallization measurements. Emphasis was laid on the studies of influence of compositional heterogeneity on the morphology and properties of these segmented copolymers. It was found that the solution cast specimens of the more heterogeneous sample exhibit better segregation of segments

high crystallinity and melting temperature.They have higher thermal stability of mechanical properties at small deformations.However

they are less stable against large deformations and may become softer than the more homogeneous ones.