Kinetics study of cold-crystallization of poly(ethylene terephthalate) nanocomposites with multi-walled carbon nanotubes
Kinetics study of cold-crystallization of poly(ethylene terephthalate) nanocomposites with multi-walled carbon nanotubes
复制标题
DOI：
10.1016/j.tca.2009.04.005
复制
发表时间：
2009-09-10
影响因子：
3.5
通讯作者：
Chrissafis, K.
中科院分区：
文献类型：
--
作者：
Antoniadis, G.;Paraskevopoulos, K. M.;Chrissafis, K.
采用原位聚合法制备了一系列PET/MWCNTs纳米复合材料。采用两段熔融缩聚法合成了聚对苯二甲酸乙二酯（PET）。用Kissinger和Ozawa-Flynn-Wall（OFW）方法计算的纳米复合材料的活化能值大于原始PET的活化能值。这些值对于PET-0%MWCNT为107.9kJ/mol，对于PET-1%MWCNT为154.0kJ/mol，这是所有值中较大的值。Avrami图呈现线性部分，几乎彼此平行，随后在较大温度下出现偏差。从Ozawa图中仅获得PET-0.25%MWCNT的直细粉，至少对于三种不同的加热速率。从Avrami，Malek和Ozawa图的转化程度上的活化能的依赖性，给出的动力学描述的PET/MWCNTs的冷结晶不能只使用一个结晶机制，服从Avrami方程的迹象。仅对于PET-0.25，一种结晶机理可至少用于结晶转化的主要部分。是的为了描述它们的结晶机理，必须使用具有不同活化能的至少两种机理。这两种机制可能参与了不同纳米复合材料不同程度的结晶转化。(C)2009 Elsevier B. V.保留所有权利。
A series of PET/MWCNTs nanocomposites were prepared by in situ polymerization using different amounts of multi-walled carbon nanotubes (MWCNTs). The polymerization of poly(ethylene terephthalate) (PET) was prepared by the two-stage melt polycondensation method. The values of the activation energy of the nanocomposites, as calculated with the Kissinger's and Ozawa-Flynn-Wall (OFW) methods, are larger than the ones of pristine PET. These values are 107.9 kJ/mol for PET-0% MWCNTS and 154.0 kJ/mol for PET-1% MWCNTs which is the larger value among all. Avrami plots present a linear portion, almost parallel to each other, which is followed by a deviation at larger temperatures. Straight fines are obtained from Ozawa plots only for PET-0.25% MWCNTs at least for three different heating rates. The dependence of the activation energy on the degree of conversion, from the Avrami, Malek and Ozawa plots, gives indications that for the kinetic description of the cold-crystallization of PET/MWCNTs cannot be used only one crystallization mechanism which obeys to Avrami equation. Only for the PET-0.25 one crystallization mechanism can be used at least for the major part of the crystallization conversion. So. in order to describe their crystallization mechanisms at least two mechanisms with different activation energies must be used. These two mechanisms maybe are taking part in different degree of crystallization conversions for every nanocomposite. (C) 2009 Elsevier B.V. All rights reserved.