The inexistence of epitaxial relationship between stereocomplex and α crystal of poly(lactic acid): Direct experimental evidence
The inexistence of epitaxial relationship between stereocomplex and α crystal of poly(lactic acid): Direct experimental evidence
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聚乳酸立体络合物与α晶体不存在外延关系：直接实验证据
DOI：
10.1016/j.polymer.2013.02.010
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发表时间：
2013-03-22
期刊：
影响因子：
4.6
通讯作者：
Wang, Dujin
中科院分区：
文献类型：
--
作者：
Wen, Tao;Xiong, Zujiang;Wang, Dujin
为了更清楚地了解PLA的均相晶体（α型）与其立体复合物（SC）晶体之间的相互作用，本文研究了PLA均聚物在SC和均聚物纤维表面驱动力作用下的结晶行为。结果表明，沿着SC纤维方向的横截面成核密度远低于沿着均聚物方向的成核密度。在较高的结晶温度下，SC和均聚物纤维之间的这种形态差异变得更加明显。在160 ℃时，PLLA在SC纤维上的结晶诱导期（t（i））比沿着均聚物的长5倍。但是，如果共混纤维主要含有α晶，则其可以表现出与均聚物纤维一样的高成核能力。TEM选区电子衍射（SAED）的结果也表明，α晶体的组织和取向与SC衬底的存在无关。我们的结果清楚地表明，PLA SC和α晶体之间没有外延关系。(c)2013爱思唯尔有限公司保留所有权利。
In order to obtain a clear understanding to the interplay between the homogeneous crystal (alpha form) of PLA and its stereocomplex (SC) crystal, the crystalline behavior of PLA homopolymer under the surface drive force of SC and homopolymer fibers has been investigated in the present work. It was found that the nucleating density of the transcrystallization layer along the SC fiber was much lower than that along the homopolymer ones. Such morphologic difference between transcrystallization induced by SC and homopolymer fibers became more pronounced at higher crystallization temperature. The crystallization induction period (t(i)) of PLLA onto SC fiber was five times longer than that along homopolymer ones at 160 degrees C. However, if the blend fiber was predominantly containing alpha crystal, it could exhibit high nucleating capability as well as the homopolymer fibers. The results of TEM selected area electron diffraction (SAED) also revealed that the organization and orientation of alpha crystal were independent with the presence of SC substrate. Our results clearly indicated that there is no epitaxial relationship between PLA SC and alpha crystal. (c) 2013 Elsevier Ltd. All rights reserved.