Temperature modulated calorimetry and dielectric spectroscopy in the glass transition region of polymers
Temperature modulated calorimetry and dielectric spectroscopy in the glass transition region of polymers
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DOI：
10.1007/bf01983612
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发表时间：
1996-03-01
期刊：
影响因子：
--
通讯作者：
Schick, C
中科院分区：
文献类型：
--
作者：
Hensel, A;Dobbertin, J;Schick, C
用线性响应方法描述了非晶和半晶聚合物玻璃化过渡区温度调制DSC的结果。讨论了复热容的实部和虚部。并将所得结果与介电光谱的结果进行了比较。频率相关的玻璃化转变温度可以用vft方程拟合。与介电测量值相比，转换频率降低了0.5到1个数量级。标准DSC的冷却速率被转换成频率。玻璃化转变温度也由温度调制测量的vft拟合近似。讨论了非晶和半晶样品在曲线形状上的差异。
The results from temperature modulated DSC in the glass transition region of amorphous and semicrystalline polymers are described with the linear response approach. The real and the imaginary part of the complex heat capacity are discussed. The findings are compared with those of dielectric spectroscopy. The frequency dependent glass transition temperature can be fitted with a VFT-equation. The transition frequencies are decreased by 0.5 to 1 orders of magnitude compared to dielectric measurements. Cooling rates from standard DSC are transformed into frequencies. The glass transition temperatures are also approximated by the VFT-fit from the temperature modulated measurements. The differences in the shape of the curves from amorphous and semicrystalline samples are discussed.