SEBS-b-TPU and nanoclay: effective compatibilizers for promotion of the interfacial adhesion and properties of immiscible SEBS/TPU blends

High-performance polystyrene-b-poly (ethylene-butylene)-b-polystyrene/thermoplastic polyurethane (SEBS/TPU) blends containing polyurethane blocked styrene-ethylene-butylene-styrene (SEBS-b-TPU) and SEBS-b-TPU/clay were obtained by melt mixing. The influence of SEBS-b-TPU and nanoclay content on morphology, mechanical, thermal, rheological and abrasion behavior of the SEBS/TPU blends were investigated. SEM results indicated that the domain size of the TPU phase was remarkably reduced by the presence of SEBS-b-TPU. Moreover, the addition of clay further improved the extent of mixing. TEM and SEM-EDX revealed that nanoclays were preferentially located in and along the outer edge of the TPU phase with an intercalated/exfoliated structure. TGA results showed that the degradation temperatures (T-5%) were increased by 12.3 degrees C and 20.8 degrees C for SEBS/TPU/SEBS-b-TPU-7% and SEBS/TPU/SEBS-b-TPU/clay-3% nanocomposites, respectively, compared with that of SEBS/TPU. There was also an improvement in mechanical and rheological properties as expected. Meanwhile, the abrasion resistance of SEBS/TPU blends was considerably enhanced by the presence of SEBS-b-TPU/clay, the DIN volume loss decreased by as much as 56%, which can be attributed to the dispersion of the clay platelets in nanoscales as well as the enhanced interfacial adhesion. These superior properties of the SEBS/TPU blends are important for many applications.

Automated summary

High-performance SEBS/TPU blends containing SEBS-b-TPU and clay were obtained by melt mixing, resulting in improved morphology, mechanical, thermal, rheological, and abrasion behavior. The addition of SEBS-b-TPU reduced the domain size of the TPU phase and the presence of clay further enhanced mixing, leading to increased degradation temperatures and improved mechanical and rheological properties. The abrasion resistance of the blends was significantly enhanced by the presence of SEBS-b-TPU/clay, attributed to the dispersion of clay platelets in nanoscales and enhanced interfacial adhesion.