ATRP of tert-Butoxycarbonylaminomethyl acrylate (tBAMA): Well-Defined Precursors for Polyelectrolytes of Tunable Charge

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• 作者：Mark Billing ; Felix H. Schacher
• 刊名：Macromolecules
• 出版年：2016
• 出版时间：May 24, 2016
• 年：2016
• 卷：49
• 期：10
• 页码：3696-3705
• 全文大小：441K
• 年卷期：0
• ISSN：1520-5835

文摘

We present the controlled radical polymerization of homo and block copolymers containing tert-butoxycarbonylaminomethyl acrylate (tBAMA) via ATRP. By varying monomer concentration, solvent, reaction temperature, and ligand (PMDETA, HMTETA, TPMA, Me₆TREN and dNbpy), suitable reaction conditions could be established. Moderate control over the polymerization was achieved when using Me₆TREN as ligand, whereas this could be drastically improved in case of dNbpy. For block copolymerization, a variety of macroinitiators (polystyrene, poly(n-butyl acrylate), poly(ethylene oxide)) were prepared via ATRP or end group modification. Block extensions resulted in well-defined block copolymers with moderately low dispersity indices (M_w/M_n = 1.12–1.36). In addition, the use of a bromine-functionalized porp core as multifunctional initiator (n = 4) resulted in monomodal star-shaped PtBAMA. The applied homopolymers, macroinitiators, and diblock copolymers were characterized by ¹H NMR, ¹³C NMR and SEC—as well as MALDI–ToF for one PtBAMA homopolymer. We have already shown for materials prepared using free radical polymerization that the presence of orthogonal protective groups for either −NH₂ or −COOH moiety of PtBAMA allows for selective deprotection, thereby generating polyelectrolytes of different charge and charge density. The herein presented PtBAMA of moderate dispersity and different architecture will enable the preparation of similar albeit better defined materials in the near future.