Dendritic-linear copolymers via diels-alder cycloaddition

Abstract

Dendronized polymers are growing as an area in the synthesis of macromolecular architectures. Widespread interest and applications of such structural designs necessitates development of novel synthetic methods. In order to synthesize dendronized polymers, three different ways, macromonomer, graft-to and graft-from, are well-known methods. The graft-to method was chosen for this study. Work involves three parts: Dendronized polymers via only Diels-Alder reaction, orthogonal click-click dendronization of polymers and bis-dendritic polyethylene (PE) via ROMP and click chemistry. A styrene based polymer appended with anthracene groups for the first study and both anthracene and azido as reactive side chains for the second study were synthesized. First through third generation polyester dendrons containing furan protected maleimide groups at their focal point and polyaryl dendrons containing acetylene at their focal point were synthesized. Polyester dendrons were combined to the polymer containing only anthracene via Diels-Alder reaction and some special studies were done related to these. Secondly, polymers containing both anthracene groups and azide groups as orthogonal reactive side chains were coupled with two different dendrons via Cu(I) catalyzed Huisgen reaction and Diels-Alder reaction. Azide containing PE was synthesized with special chain transfer agent (CTA) via ROMP. Polyaryl dendrons containing acetylene at their focal point were combined to this polymer via Cu(I) catalyzed Huisgen click reaction resulting in a bis-dendritic polymer.