SAXS and TEM measurements are employed in order to study the morphology of poly(styrene)-block-poly(ethene-co-but-1-ene)-block-poly(styrene) (SEBS) with 29 wt % styrene (Kraton G1652) in bulk and at interfaces to different polymers. Temperature-dependent SAXS measurements of the SEBS bulk sample reveal that PS cylinders are hexagonally packed in the EB matrix. The lattice constant increases during cooling from 200 to 120 °C from 27.5 to 29.5 nm and simultaneously an increase of the cylinder radius occurs from 7 to 7.5 nm. The lattice constant obtained by SAXS is in agreement with TEM measurements on ultrathin sections of the bulk sample. TEM tilting experiments confirm the existence of cylindrical microdomains in the SEBS bulk phase. Furthermore, the behavior of SEBS at the interface with various polymers is studied by TEM and peel tests. TEM measurements show that SEBS forms one lamella at the interface PS homopolymer having a molecular weight much larger than the PS blocks. This results only in a very w...