hrvatski

Kinetika izotermne kristalizacije za TPU/PP mješavine

The kinetics of isothermal crystallization and crystalline structure of TPU/PP and TPU/PP/T blends of different composition ratio (80/20, 50/50 and 20/80 wt %) were studied under isotermal condition by differential scanning calorimetry (DSC). Crystalization studies were carried out in the temperature range of 116°C to 132°C. It was found that crystallization is faster for TPU/PP/T blends. Isothermal crystallization kinetics were described by means of the Avrami equation. The effects of different isothermal temperature were studied comparing the values of kinetic parameters such as the Avrami exponent, n, the kinetic constant of the crystallization rate, K, and the half-time of crystallization, t1/2. The Avramy exponent was evaluated to be in the range of 1, 18 - 2, 31. This results indicated the two-dimensional growth of crystalline units. The isothermal crystallization kinetics showed that the addition of talc increased the isothermal crystallization temperature and increased the crystallization rate, K, of TPU/PP blends. For a given crystallization temperature, the crystallization half-time , t1/2, in the TPU/PP/T blends was lower than the corresponding value for TPU/PP blends.

polipropilen, termoplastični poliuretan, diferencijalna pretražna kalorimetrija, izotermna kristalizacija, kinetika kristalizacije

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