New Polyethylene Macroinitiators and Their Subsequent Grafting by Atom Transfer Radical Polymerization

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• 作者：Yanika Schneider ; Jason D. Azoulay ; Robert C. Coffin ; Guillermo C. Bazan
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：August 13, 2008
• 年：2008
• 卷：130
• 期：32
• 页码：10464-10465
• 全文大小：140K
• 年卷期：v.130,no.32(August 13, 2008)
• ISSN：1520-5126

文摘

A semicrystalline polyethylene (PE) macroinitiator was prepared by copolymerizing ethylene and an inititating monomer (5-norbornen-2-yl-2′-bromo-2′-methyl propanoate) (3) using [N-(2,6-diisopropylphenyl)-2-(2,6-diisopropylphenylimino)isobutanamidato]-Ni(η¹-CH₂Ph)(PMe₃) (1) and Ni(COD)₂ (bis(1,5-cyclooctadiene)-nickel) (2). Although 3 decomposes Ni(COD)₂, if the initiating species (1/2) are exposed to ethylene for a period of time, t₁, and then 3 is introduced for another period of time, t₂, the polymerization takes place in a controlled manner. Variations in temperature, pressure, and [3] afford a great deal of control over the composition and architecture of the PE macroinitiator. Subsequent grafting with methyl methacrylate (MMA) yields PE-graft-PMMA with narrow polydispersities and increasing PMMA content at longer reaction times. Because the products are semicrystalline materials with high melting points, they are anticipated to function as blend compatibilizers for linear polyethylene.