The influence of filler treatment on the mechanical properties and phase behavior of thermoplastic polyurethane/polypropylene blends

Thermoplastic polyurethane (TPU) and isotactic polypropylene (iPP) composites and their talc reinforced blends containing untreated and silane treated talc were investigated. The talc surface was modified with organosilane coupling agent in order to improve the polymer-filler interface interaction. TPU has been blended with iPP in a twin screw extruder and samples for investigation were prepared by injection moulding at different concentrations. The neat polymers, composites and blends were characterized with DMA, XRD, FTIR and tensile testing. The obtained results showed that mechanical properties of the talc filled TPU and iPP composites and TPU/iPP blends were improved with the addition of untreated and silane treated talc. The storage modulus of the TPU/iPP blends increased with the addition of untreated and silane treated talc, due to a stiffer interface which talc generated in the polymer matrix. The comparison among samples filled with untreated and silane treated talc filler showed that the polymer composites and TPU/iPP blends filled with silane treated talc displayed better mechanical properties. Silane addition improves the adhesion between the filler and the polymer matrix.