The effect of temperature on nascent morphology of polyethylene polymerized over solution-phase flat model catalysts

doi:10.1016/j.polymer.2009.05.043

CORC > 化学研究所 > 中国科学院化学研究所

	The effect of temperature on nascent morphology of polyethylene polymerized over solution-phase flat model catalysts
	Jiang, Shidong 2; Kong, Bin 2; Han, Wei 1; Thune, Peter C.1; Yang, Xiaozhen 2; Loos, Joachim 1; Yan, Shouke 2,3
刊名	POLYMER
	2009-07-17
卷号	50 期号:15 页码:3810-3818
关键词	Polyethylene Polymerization Structure And Morphology
ISSN号	0032-3861
DOI	10.1016/j.polymer.2009.05.043
英文摘要	The structure and morphology of polyethylene (PE) produced during solution polymerization using bis(imino)pyridyl metal catalysts supported by flat SiO(2)/Si(100) wafers were investigated by atomic force microscopy (AFM) and electron diffraction. Depending on the polymerization temperature, ranging from RT to 85 degrees C, different morphologies of the nascent PE have been observed. "Sea weed" like supermolecular structures are the predominant nascent morphologies of the PE polymerized at low temperatures. This should be associated with the high PE yield and high nucleation rate at low temperature; the catalyst is highly active and the PE macromolecules have low solubility in toluene and nucleate immediately after formation. With increasing polymerization temperature, e.g. at 60 or 70 degrees C, larger single crystals with roughly a lozenge shape but saw-tooth-like facets have been created. The multilayer overgrowth of the PE crystals demonstrates that the generated PE materials exceed what is required for single layer crystal growth. At 85 degrees C, decreasing crystal growth rate results in the formation of small PE single crystals. At the same time, the high solubility of the PE in toluene results in continuous diffusion of the macromolecules to the existing PE crystals and therefore single crystals in regular truncated lozenge shape have been formed. Electron diffraction indicates that in the whole temperature range, PE crystallizes in flat-on crystals in chain-folded structure with different chain folding stem length. (C) 2009 Elsevier Ltd. All rights reserved.
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000268306700050
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/66845]
专题	中国科学院化学研究所
通讯作者	Loos, Joachim
作者单位	1.Eindhoven Univ Technol, Dept Chem Engn & Chem, NL-5600 MB Eindhoven, Netherlands 2.Chinese Acad Sci, Inst Chem, State Key Lab Polymer Phys & Chem, Beijing 100190, Peoples R China 3.Beijing Univ Chem Technol, State Key Lab Chem Resource Engn, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Jiang, Shidong,Kong, Bin,Han, Wei,et al. The effect of temperature on nascent morphology of polyethylene polymerized over solution-phase flat model catalysts[J]. POLYMER,2009,50(15):3810-3818.
APA	Jiang, Shidong.,Kong, Bin.,Han, Wei.,Thune, Peter C..,Yang, Xiaozhen.,...&Yan, Shouke.(2009).The effect of temperature on nascent morphology of polyethylene polymerized over solution-phase flat model catalysts.POLYMER,50(15),3810-3818.
MLA	Jiang, Shidong,et al."The effect of temperature on nascent morphology of polyethylene polymerized over solution-phase flat model catalysts".POLYMER 50.15(2009):3810-3818.