Temperature modulated DSC and DSC studies on the origin of double melting peaks in poly(ether ether ketone)
Temperature modulated DSC and DSC studies on the origin of double melting peaks in poly(ether ether ketone)
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DOI：
10.1016/j.polymer.2003.10.009
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发表时间：
2003-12
期刊：
影响因子：
4.6
通讯作者：
C. Wei;Ming Chen;Feng-Er Yu
中科院分区：
文献类型：
--
作者：
C. Wei;Ming Chen;Feng-Er Yu
采用差示扫描量热法（DSC）和温度调制DSC（TMDSC）研究了聚醚醚酮的结晶动力学和熔融行为。等温结晶在290 ° C和320 °C之间进行。Avrami指数和平稳时间由Avrami分析确定。通过以1分钟为步长增加等温结晶时间，获得了出现双熔融峰所需的最小诱导时间。结果发现，平稳时间并不代表单或双熔融峰行为的界限。为了阐明双熔融峰的行为，样品在280和320 °C之间等温结晶10 min，然后以2 °C/min的速度加热至380 °C。从TMDSC结果来看，非可逆曲线中的放热行为支持在Tc≤310 ° C下的熔融-再结晶机制。 另一方面，对于Tcat 320 °C没有放热流动支持两种不同形态的机制。随着等温结晶温度从280 °C升高到320 °C，熔融-再结晶对上熔融峰的贡献逐渐减小，最后消失。
Crystallization kinetics and melting behavior of poly(ether ether ketone) were studied by differential scanning calorimetry (DSC) and temperature-modulated DSC (TMDSC). The isothermal crystallization was performed between 290 and 320 °C. The Avrami exponents and the level off time were determined from the Avrami analysis. The minimum induction time required for the occurrence of double melting peaks was obtained by increasing the isothermal crystallization time in steps of one minute. It was found that the level off time did not represent the delimitation of single- or double-melting peak behavior. To elucidate the behavior of double melting peaks, the samples were crystallized isothermally between 280 and 320 °C for 10 min, and then they were heated to 380 °C at 2 °C/min. From the TMDSC results, the exothermic behavior in the non-reversing curves supports the mechanism of melting–recrystallization at Tc≤310 ° C . On the other hand, no exothermic flow for Tcat 320 °C supports the mechanism of two different morphologies. As the isothermal crystallization temperature increased from 280 to 320 °C, the contribution of melting–recrystallization to the upper melting peak gradually decreased, and finally disappeared.