Enhanced Crystallization and Properties of Poly(ethylene terephthalate) nanocomposites with Zeolites from 3D to 2D Topologies
Enhanced Crystallization and Properties of Poly(ethylene terephthalate) nanocomposites with Zeolites from 3D to 2D Topologies
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DOI：
10.1016/j.jiec.2022.02.038
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发表时间：
2022-02
影响因子：
6.1
通讯作者：
Wei Zhang;Hongbin Zhang;Liping Yang;Yi-Hua Tang;P. Tang
中科院分区：
文献类型：
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作者：
Wei Zhang;Hongbin Zhang;Liping Yang;Yi-Hua Tang;P. Tang
为了改善聚对苯二甲酸乙二醇酯(PET)结晶速度慢、成型周期长的缺点，采用熔融共混法对含有少量不同结构沸石的系列PET纳米复合材料进行了共混。通过非等温结晶、等温结晶、纳米粒子分散性的定量评价和纳米粒子形态的定量评价，分析了三维分子筛Y、ZSM-5和二维分子筛MCM-22P对PET结晶方式的成核影响。结果表明，由于沸石具有较大的比表面积和较好的分散性，所有PET/沸石纳米复合材料的结晶温度和结晶速度均高于PET。其中，PET/MCM-22P纳米复合材料显著改善了复合材料的结晶行为、热稳定性和阻氧性能，这与MCM-22P的层状形态和MCM-22P与PET之间的氢键作用有关。结果表明，在熔融共混中，MCM-22P可以通过剥离为PET提供更多的异相成核点。利用Mozhishen方法、Avrami方程和Hoffman-Lauritzen理论对MCM-22P的成核机理进行了研究。结果表明，MCM-22P的加入降低了PET结晶过程中成核自由能和折叠表面自由能，从而提高了共混物的结晶度。
To improve the low crystallization rate and long molding cycle of Poly(ethylene terephthalate) (PET), series of PET nanocomposites incorporated small quantities of zeolites with different topologies were blended by melt compounding. The nucleation influence of 3-dimensional zeolites Y, ZSM-5 and 2-dimensional zeolite MCM-22P on the crystallization manner of PET was analyzed by non-isothermal and isothermal crystallization, quantitative evaluation of nanoparticle dispersion and morphology of nanoparticles. The results show that all PET/zeolite nanocomposites exhibit higher crystallization temperature and faster crystallization rate than PET due to large specific surface area of zeolites and their superior dispersion in the PET matrix. Among them, PET/MCM-22P nanocomposites remarkably improved the crystallization behavior, thermal stability and oxygen barrier properties, which is related to the layered morphology of MCM-22P and hydrogen bond interactions between MCM-22P and PET. It is revealed that MCM-22P can provide more heterogeneous nucleation sites for PET by exfoliation in melting compounding. Furthermore, the nucleation mechanism induced by MCM-22P was investigated by the means of Mozhishen method, Avrami equation and theory of Hoffman-Lauritzen. The results indicate that the incorporation of MCM-22P can decrease the free energy of nucleation and fold surface in PET crystallization process, thus improving the crystallinity.