Isothermal crystallization kinetics and melting behavior of poly(ethylene terephthalate)/barite nanocomposites
Isothermal crystallization kinetics and melting behavior of poly(ethylene terephthalate)/barite nanocomposites
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DOI：
10.1002/polb.21669
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发表时间：
2009-04
期刊：
影响因子：
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通讯作者：
Chunhua Ge;P. Ding;Liyi Shi;Jifang Fu
中科院分区：
文献类型：
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作者：
Chunhua Ge;P. Ding;Liyi Shi;Jifang Fu
采用熔融共混法制备了聚对苯二甲酸乙二醇酯（PET）/重晶石纳米复合材料。采用DMA和DSC研究了PET-重晶石界面相互作用对动态力学性能和结晶性能的影响。结果表明，重晶石具有成核剂的作用，表面改性后的重晶石（SABarite）具有更高的成核活性。由于PET链和SABarite纳米颗粒之间存在较强的界面相互作用，SABarite纳米颗粒诱导了优先片层取向，而WAXD测定的Barite填充PET中的情况并非如此。对于PET/Barite纳米复合材料，Avrami指数n随着结晶温度的升高而增大。在相同的晶化温度下，n值随SABarite含量的增加而减小，表明成核活性增强。Avrami分析表明，成核机制是不同的。由Arrhenius方程确定的PET/SABarite纳米复合材料的活化能显著降低，证实PET链与SABarite纳米颗粒之间的强界面相互作用可以降低成核的结晶自由能垒。在等温结晶后的DSC扫描中发现了双熔融行为，这可能是由于不同结晶过程中产生的二次层状结构或再结晶后的不完全微晶的熔融所致。© 2009威利期刊公司.聚合物科学杂志B部分：聚合物物理47：655-668，2009
Poly(ethylene terephthalate) (PET)/Barite nanocomposites were prepared by direct melt compounding. The effects of PET-Barite interfacial interaction on the dynamic mechanical properties and crystallization were investigated by DMA and DSC. The results showed that Barite can act as a nucleating agent and the nucleation activity can be increased when the Barite was surface-modified (SABarite). SABarite nanoparticles induced preferential lamellae orientation because of the strong interfacial interaction between PET chains and SABarite nanoparticles, which was not the case in Barite filled PET as determined by WAXD. For PET/Barite nanocomposites, the Avrami exponent n increased with increasing crystallization temperature. Although at the same crystallization temperature, the n value will decrease with increasing SABarite content, indicating of the enhancement of the nucleation activity. Avrami analyses suggest that the nucleation mechanism is different. The activation energy determined from Arrhenius equation reduced dramatically for PET/SABarite nanocomposite, confirming the strong interfacial interaction between PET chains and SABarite nanoparticles can reduce the crystallization free energy barrier for nucleus formation. In the DSC scan after isothermal crystallization process, double melting behavior was found. And the double endotherms could be attributed to the melting of recrystallized less perfect crystallites or the secondary lamellae produced during different crystallization processes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 655–668, 2009