Microphase separation of segmented poly(ether-ester) multiblock copolymer films crystallised under high strain rates

The morphology of the multiblock copolymer poly(ether-ester) (PBT/PTMO), based on PET as the hard and PTMO as the soft segments in uniaxially oriented fibres, were studied by transmission election microscopy (TEM), differential scanning calorimetry (DSC), and small- and wide-angle X-ray scattering (SAXS and WAXS). Ultra-thin films of copolymers, approximately 100 Mm thick were prepared by a special drawing technique which provides a high extensional flow gradient and supercooling during crystallisation. TEM studies of the thermoplastic elastomers (PEE) showed super-molecular structures of different polylether esters with a hard segment content between 50 and 80 wt.%. In all samples a multistructured morphology consisting of two phases tons found, including lamella like crystals. Art optimal drawing temperature of about 170 degreesC was found to provide the highest degree of crystal orientation. Annealing at a temperature of 180 degreesC for 1 hour led to the transformation of the lamellae from nematic to smectic structural ol der. The annealing, carried out on highly oriented samples with fired or free olds, creates small differences in the specific melting points, as the macromolecules in amorphous phase ave absolutely relaxed.