Lamellar morphology of polyethylene: Electron microscopy of a melt‐crystallized sharp fraction
作者:
D. T. Grubb,
A. Keller,
期刊:
Journal of Polymer Science: Polymer Physics Edition
(WILEY Available online 1980)
卷期:
Volume 18,
issue 2
页码: 207-216
ISSN:0098-1273
年代: 1980
DOI:10.1002/pol.1980.180180203
出版商: John Wiley&Sons, Inc.
数据来源: WILEY
摘要:
AbstractThe morphology of linear polyethylene ofMw/Mn1.19 crystallized isothermally from the melt has been investigated. Electron microscopy (EM) of stained thin sections gave exceptionally well‐defined images. There were no qualitative differences between Regime I and Regime II crystallization, but the lamellae grown at lower supercooling were thicker, larger, and had fewer spiral growths per unit area of fold surface. Small‐angle x‐ray scattering indicated a much sharper distribution of lamellar thicknesses than EM and Raman LAM did. This is evidence of the complementary nature of the techniques and not a contradiction. EM also revealed nonrepresentative features in detail. There were extremely thin lamellae formed on cooling, indicating molecular weight segregation even in this fractionated material, and there were extremely thick lamellae, attributed to isothermal thickening. As the representative lamellae are also supposed to have thickened isothermally, this raises the issue of when and how the lamellae which are theprimaryproducts of crystallization can be ident
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