Effects of hydrogen-bonding density on polyamide crystallization kinetics
Effects of hydrogen-bonding density on polyamide crystallization kinetics
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DOI：
10.1016/j.polymer.2020.122165
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发表时间：
2020-02-17
期刊：
影响因子：
4.6
通讯作者：
Hu, Wenbing
中科院分区：
文献类型：
--
作者：
Li, Xiaoheng;He, Yucheng;Hu, Wenbing
采用Flash DSC-1芯片式快速扫描量热仪在宽温区对尼龙46、尼龙66、尼龙610、尼龙612、尼龙1012和尼龙12等6种聚酰胺/尼龙（PA）样品的等温结晶速率进行了比较。半结晶时间与结晶温度的双抛物线曲线表明，PA 46结晶相对较快，这是由于其高的氢键密度有利于在高温区结晶的热力学驱动力，而PA 1012和PA 12结晶相对较快，这是由于其低的氢键密度有利于在低温区结晶的短程扩散。此外，两个抛物线曲率的6个样品之间的交叉温度遵循其序列的氢键密度，和Avrami指数揭示了一个潜在的切换模式之间的异质和均匀的晶体成核。
We employed Flash DSC1 apparatus for fast-scan chip-calorimeter measurement in a broad temperature range to compare the isothermal crystallization rates among six polyamide/nylon (PA) samples, i.e. PA 46, PA 66, PA 610, PA 612, PA 1012 and PA 12. The double parabolic curves of crystallization half-time versus crystallization temperature revealed that PA 46 crystallizes relatively fast due to its high hydrogen-bonding density favoring thermodynamic driving forces for crystallization in the high temperature region, while PA 1012 and PA 12 crystallize relatively fast due to their low hydrogen-bonding densities favoring short-range diffusion for crystallization in the low temperature region. Furthermore, the cross-over temperatures between two parabolic curvatures of six samples follow their sequences in hydrogen-bonding density, and the Avrami indexes reveal a potential switching in the modes between heterogeneous and homogeneous crystal nucleation.