A method for analysis of the measured curves of TMDSC investigation in themelting region of polymers

The measured signal of the temperature-modulated differential scanning calo rimetry (TMDSC) is discussed in the case of polymer melting. The common dat a evaluation procedure of TMDSC-signals is the Fourier analysis. The result ing information is the amplitude and the phase shift of the first harmonic of the periodic heat flow component. It is shown that this procedure is not sufficient for quantitative discussions if deviations from the symmetric c urve shape occur in the measured heat flow curves. For polymer melting it i s demonstrated that asymmetric curves will be measured if the experimental temperature amplitude is too large. In this paper a data evaluation method is presented, which is based on the Fourier transform of the measured curves. The peaks of the first and second harmonics in the resulting spectra are used for the analysis of the asymme try of the measured curves. In the case of polymer melting this analysis yi elds the maximum temperature amplitude which follows a correct linear data evaluation. This maximum temperature amplitude depends on the material.