Direct observation of growth of lamellae and spherulites of a semicrystalline polymer by AFM
Direct observation of growth of lamellae and spherulites of a semicrystalline polymer by AFM
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DOI：
10.1021/ma000273e
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发表时间：
2001-01-16
期刊：
影响因子：
5.5
通讯作者：
Lei, YG
中科院分区：
文献类型：
--
作者：
Li, L;Chan, CM;Lei, YG
用原子力显微镜直接观察了双酚A和1，8-二溴辛烷缩聚合成的聚合物(BA-C8)在25+/-1℃下片晶和球晶的动态生长过程。在生长片层顶端测得的相移小于片层其他区域的相移。这一结果表明，片层的生长前沿比显影的片层更柔软，含有更多的缺陷。研究了片晶的生长过程和球晶的形成。观察到，通过诱导相邻的次生核，片层形成更多的片层，并发育成片状束，最后形成球晶。片层相对于BA-C8聚合物薄膜的表面是择优取向的。对次生核形成的详细观察表明，次生核的分枝只是次生核的一个暂时的生长阶段。在分叉点，次生薄片相对于母片的生长方向既可以向后扩展，也可以向前扩展。
The dynamic growth processes of lamellae and spherulites of a polymer (BA-C8) synthesized by condensation polymerization of bisphenol A and 1,8-dibromooctane were directly observed using an atomic force microscope at 25 +/- 1 degreesC. The phase shift measured at the tip of growing lamellae is lower than the phase shifts of the other regions of the lamellae. This result indicates that the growth front of a lamella is softer and contains more defects than the developed ones. The growth process of lamellae and the formation of spherulites were studied. A lamella was observed to breed more lamellae by inducing adjacent secondary nuclei and to develop into a lamellar sheaf and finally into a spherulite. The lamellae were preferentially oriented edge-on with respect to the surface of the BA-C8 polymer thin films. The detailed observations on the formation of the secondary nuclei indicated that the branching of the lamellae was only a temporary growth stage of the secondary lamellae. At the branch point, the secondary lamellae could propagate in both backward and forward directions with respect to the growth direction of the parent lamellae.