Heating rate dependence of melting peak temperature examined by DSC of heat flux type
Heating rate dependence of melting peak temperature examined by DSC of heat flux type
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DOI：
10.1007/s10973-015-4603-3
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发表时间：
2016-03
影响因子：
4.4
通讯作者：
A. Toda
中科院分区：
文献类型：
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作者：
A. Toda
用热流式差示扫描量热法研究了铟和等规聚丙烯的晶体熔融行为。熔化显示出以峰值温度的偏移与成比例的幂为特征的依赖性。功率区分有过热和无过热的熔化。对于聚合物晶体熔化，由于熔化动力学的过热，具有分数幂的宽熔化区的固有性质已被实验重新证实。另一方面，铟的晶体熔化，这应该是可以忽略不计的过热进行，显示在峰值温度的移动与范围内的功率，取决于样品的质量，这是由于仪器的热滞后预测的Mraw的模型组成的集总元件。的依赖性是由样品盘和阶段之间的热接触电阻确定的热滞后的影响，其效果已被检查的样品质量和样品盘和阶段之间的硅脂的应用程序的依赖性方面。两种不同类型的热流的定义的影响也进行了检查;简化的没有温差的时间导数的峰值温度在更快的扫描速率以类似的方式热滞后的一个明显的位移。
Crystal melting behavior of indium and isotactic polypropylene has been examined by differential scanning calorimetry of heat flux type in terms of the heating rate,, dependence. The melting shows the dependence characterized by a power,, of the shift in peak temperature in proportion to. The power,, differentiates the melting with and without superheating. For polymer crystal melting, intrinsic nature of the broad melting region with a fractional power,, due to superheating of melting kinetics has been reconfirmed experimentally. On the other hand, the crystal melting of indium, which is supposed to proceed with negligible superheating, showed the shift in peak temperature with the power in the range of, depending on sample mass, which is due to instrumental thermal lag predicted by the Mraw’s model consisting of lumped elements. Thedependence is influenced by the thermal lag determined by the thermal contact resistance between the sample pan and the stage, the effect of which has been examined in terms of the dependence on sample mass and the application of silicone grease between the sample pan and the stage. The influence of two different types of the definition of heat flow has also been examined; the simplified one without the time derivative of temperature difference showed an apparent shift in peak temperature at faster scan rates in a similar way as that of thermal lag.