The study of morphology,thermal and thermo‐mechanical properties of compatibilized TPU/SAN blends

The compatibilizing efficiency of three different compatibilizers in thermoplastic polyurethane/styrene‐co‐acrylonitrile (TPU/SAN) blends was investigated after their incorporation via melt‐mixing. The compatibilizers studied were poly‐ε‐caprolactone (PCL), a mixture of polystyrene‐block‐polycaprolactone (PS‐b‐PCL) and polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA), and a mixture of polyisoprene‐block‐polycaprolactone (PI‐b‐PCL) and polybutadiene‐block‐poly(methyl methacrylate) (PB‐b‐PMMA). All compatibilizers were synthesized by living anionic polymerization. Investigations of thermal and thermo‐mechanical properties performed by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DTMA), respectively, were systematically classified into two groups, i.e. blends of TPU or SAN with 20 wt% of different compatibilizers (so‐called limit conditions) and TPU/SAN 25/75 blends with 5 wt% of different compatibilizers. In order to determine the compatibilizer's location, morphology of TPU/SAN 25/75 blends was studied with transmission electron microscopy (TEM). Different compatibilization activity was found for different systems. Blends compatibilized with PCL showed superior properties over the other blends. Polym. Eng. Sci. 44:838–852, 2004. © 2004 Society of Plastics Engineers.