Isothermal Crystallization Kinetics of Polypropylene by Differential Scanning Calorimetry. I. Experimental Conditions
Por:
Hernández-Sánchez F., Del Castillo L.F., Vera-Graziano R.
Publicada:
1 ene 2004
Resumen:
Reliable isothermal crystallization kinetic studies can be achieved by differential scanning calorimetric techniques only under restricted conditions. In the case of isotactic polypropylene, our results indicate that those conditions are met in the range of 3°C below the isothermal crystallization temperature Tc. Experimentally, it is only in this range when the complete crystallization peak can be registered by the DSC and depicted in a thermogram. Just around this temperature interval, the Avrami exponent n = 3 for bulk crystallization, whereas for any other test the isothermal temperature Tit, nonisothermal conditions prevail and the Avrami exponent deviates from the expected value. © 2004 Wiley Periodicals, Inc.
Filiaciones:
Hernández-Sánchez F.:
Ctro. de Invest. Cie. Yucatan, A. P. 87, Cordemex, Merida, Yucatan, Mexico
Del Castillo L.F.:
Inst. de Invest. en Materiales, UNAM, A. P.70-360, Coyoacán 04510, D.F., Mexico
Vera-Graziano R.:
Inst. de Invest. en Materiales, UNAM, A. P.70-360, Coyoacán 04510, D.F., Mexico
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