Crystallization kinetics of polyamide 11 in the presence of sepiolite and montmorillonite nanofillers
Crystallization kinetics of polyamide 11 in the presence of sepiolite and montmorillonite nanofillers
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DOI：
10.1007/s00396-016-3874-y
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发表时间：
2016-04
影响因子：
2.4
通讯作者：
Katalee Jariyavidyanont;W. Focke;R. Androsch
中科院分区：
文献类型：
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作者：
Katalee Jariyavidyanont;W. Focke;R. Androsch
采用常规差示扫描量热法（DSC）和快速扫描芯片量热法（FSC）在较宽的温度和冷却速率范围内研究了海泡石和有机改性蒙脱土纳米填料存在下聚酰胺11（PA 11）的结晶动力学。在低冷却速率下，纳米填料的存在对PA 11的结晶温度具有可忽略的影响。然而，在快速冷却条件下，检测到纳米填料的明显成核效应。在含有海泡石和蒙脱石的纳米复合材料中，抑制结晶的临界冷却速率分别从600 K s-1增加到约1000和3000 K s-1。无论用于熔体固化的冷却速率如何，在纳米复合材料中，PA 11的结晶度比纯PA 11高5- 10%，其中含蒙脱石的体系获得最高值。通过分析等温结晶的半衰期和球晶超结构，证实了纳米填料对PA 11结晶的成核作用。所有的测量都证明了在2.5m%的纳米填料的负载下的成核效率的饱和。
The crystallization kinetics of polyamide 11 (PA 11) in the presence of sepiolite and organo-modified montmorillonite nanofillers has been studied in a wide range of temperatures and cooling rates by conventional differential scanning calorimetry (DSC) and fast scanning chip calorimetry (FSC). The presence of the nanofillers has a negligible effect on the crystallization temperature of PA 11 at low cooling rates. However, at rapid cooling conditions a distinct nucleating effect of the nanofillers is detected. The critical cooling rate to suppress crystallization increases from 600 K s−1to about 1000 and 3000 K s−1in nanocomposites containing sepiolite and montmorillonite, respectively. Regardless of the cooling rate applied for solidification of the melt, in the nanocomposites the crystallinity of PA 11 is 5–10 % higher than in neat PA 11, with the highest values obtained for the montmorillonite-containing system. The nucleating effect of the nanofillers onto the crystallization of the PA 11 is confirmed by analysis of the half-times of isothermal crystallization and by analysis of the spherulitic superstructure. All measurements proved a saturation of the nucleation efficiency at a loading of the nanofiller of 2.5 m%.