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-e-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.