Highly Orthogonal Functionalization of ADMET Polymers via Photo-Induced Diels鈥揂lder Reactions

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• 作者：Matthias Winkler ; Jan O. Mueller ; Kim K. Oehlenschlaeger ; Lucas Montero de Espinosa ; Michael A. R. Meier ; Christopher Barner-Kowollik
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：June 26, 2012
• 年：2012
• 卷：45
• 期：12
• 页码：5012-5019
• 全文大小：403K
• 年卷期：v.45,no.12(June 26, 2012)
• ISSN：1520-5835

文摘

Within the current contribution, we introduce two strategies for the catalyst-free, modular, ambient temperature synthesis of ABC triblock copolymers via photoinduced Diels鈥揂lder reactions. On the one hand, the 2-formyl-3-methylphenoxy (FMP) moiety (a second generation photoenol precursor) was employed for orthogonal polymer鈥損olymer conjugations using terminal acrylates of diblock copolymers synthesized via acyclic-diene-metathesis (ADMET) polymerizations to directly prepare triblock copolymers. On the other hand, the disparate reactivity of 2,5-dimethylbenzophenone (first generation photoenol) and the FMP moiety was exploited to selectively synthesize complex triblock copolymers (6.5 kDa鈮?M_n 鈮?1.5 kDa, 1.16鈮?PDI 鈮?1.30) via a sequential one pot approach utilizing the extraordinary orthogonality of the photoinduced Diels鈥揂lder reaction. Polymers functionalized with a photoenol (second generation) moiety were employed for conjugation reactions with polymers featuring an acrylate terminus, while polymers having a photoenol (first generation) end group were employed for selective conjugations of maleimide functional polymers. In this context, the selective head-to-tail ADMET polymerization was employed as a straightforward methodology for the preparation of bifunctional polymers having a terminal acrylate and a photoenol end-group.