| Abstract
| - We describe the synthesis, characterization, and properties of polystyrene-block-poly(ethylene-alt-propylene)-block-polyethylene (PS-b-PEP-b-PE) and polystyrene-block-poly(ethylene-alt-propylene)-block-polystyrene (PS-b-PEP-b-PS) triblock copolymers. Morphological investigations usingTEM, SEM, and SFM reveal for the PS-b-PEP-b-PE triblock copolymers a morphology consisting of PScylinders and PE crystallites within a matrix of the PEP block, whereas the PS-b-PEP-b-PS triblockcopolymer shows interconnected, distorted PS cylinders in the PEP matrix. Mechanical characterizationof these triblock copolymers demonstrated that for small strains the PS-b-PEP-b-PE triblock copolymersexhibit the aimed smaller plastic deformations, i.e. better elastic properties, compared to the polystyrene-based ABA type thermoplastic elastomer. However, at high strains the PS-b-PEP-b-PS triblock copolymershows a significantly better elastic recovery. The high plastic set at high elongations in PS-b-PEP-b-PEtriblock copolymers is attributed to the weaker resistance of the PE crystallites compared to amorphousPS domains in the PS-b-PEP-b-PS triblock copolymer.
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