Mechanical characterisation of uniaxially oriented copoly(ether ester) films

Poly(ether ester) block copolymers (PBT/PTMO), based on poly(butylene terep hthalate) (PBT) as hard segments and oxytetramethylene (PTMO) as soft segme nts were uniaxially oriented and mechanically tested. The amount of the har d segments varied between 80 wt.% PBT (El-1), 60 wt.% (El-2) and 50 wt.% (E l-3). Tensile tests and cyclic tensile tests provided valuable information about the plastic and elastic behaviour of thermally treated specimens as w ell as drawn ones. The results from these tests could be correlated to the individual microstructure and the model proposed. The morphology of the str etched block copolymers can be simply described by a model of the composite with blocks of lamellae of PBT as the hard segments incorporated into the amorphous matrix.