The influence of talc content on the thermal and mechanical properties of thermoplastic polyurethane/polypropylene blends

The influence of different talc contents on the thermal and mechanical properties of thermoplastic polyurethane/polypropylene (TPU/PP) blends was investigated. The compatibility and crystallinity of TPU/PP and TPU/PP/T blends were determined by differential scanning calorimetry (DSC). The DSC results indicated that the addition of PP in TPU/PP blends increased glass transition temperature (T g), melting temperature (T m) and crystallinity (χ c). The addition of talc has decreased T m and χ c and increased T g and crystallization temperature (T c). The effect of talc content on T g, T m and χ c was insignificant, while T c content increased. The T g of nonfilled and talc-filled blends increased suggesting that the TPU and PP are partially compatible. Thermogravimetric analysis (TGA) showed improved thermal stability of all investigated nonfilled and talc-filled TPU/PP blends in the nitrogen atmosphere. In the air atmosphere only talc-filled TPU/PP 80/20 blends show a higher thermal stability, while thermal stability decreased for TPU/PP 50/50 and increased insignificantly for TPU/PP 20/80 blends. DSC and TGA results showed improved thermal properties of talc-filled TPU/PP blends when compared with nonfilled blends. The mechanical properties of talc-filled TPU/PP 50/50 and 20/80 blends improved in terms of tensile strength and Young’s modulus, while elongation of break decreased with the addition of talc and as the talc content increased.