A NEW ANALYZING METHOD OF TEMPERATURE MODULATED DSC OF EXO-THERMAL ORENDO-THERMAL PROCESS - APPLICATION TO POLYETHYLENE CRYSTALLIZATION

A new method is presented to analyse an exothermic or endothermic proc ess with temperature modulated differential scanning calorimetry. The response of exo- or endo-thermic process against temperature modulatio n has been directly taken into account in an apparent heat capacity di fference of complex quantity. Utilizing the shift in phase lag between sample temperature and heat flow, the specific heat during the transf ormation process and the temperature coefficient of the transformation rate, e.g. crystal growth rate, are obtainable by the analysis under a reasonable assumption. The applicability of the present method has b een examined with the experimental results of polyethylene crystalliza tion. (C) 1997 Elsevier Science B.V.