Abstract:
Synthesis of polymers bearing reactive functional groups is an active area of research due to their potential applications in interdisciplinary areas such as biomaterials, material science and drug delivery. Most of the methods for accessing polymers containing reactive maleimide groups as side chains have relied on a single or multistep transformations of the functional groups in the parent polymer obtained after the polymerization reaction. Non-quantitative nature of such transformations and possible side reactions, coupled with the difficulty in reliable quantification makes it highly desirable to develop alternative methods. The methodology developed provides easy access to polymers decorated with maleimides as ‘reactive’ functional groups. The design involves synthesis of a conceptually novel acrylate based ‘latent reactive’ monomer where the maleimide double bond is protected using a Diels-Alder reaction. After the polymerization reaction, thermally induced retro Diels-Alder cycloreversion reaction quantitatively converts the protected maleimide units to their reaction form. Thus obtained reactive polymer was conjugated with octanethiol to demonstrate efficient reactivity of the maleimide side chains of the polymer. As an extension of this work, polymers containing two orthogonal functional groups as side chains, namely thiol reactive maleimide and amine reactive succinimide units were synthesized. Selective functionalization of the maleimide side chains in presence of succinimide groups by addition of octanethiol was achieved. In the second part of the study, the reactive polymers were used to fabricate reactive micro arrays via a low-cost and efficient method, namely, micro contact printing. These micro arrays were labeled with a thiol containing fluorescent-dye to show that these surfaces can be used for immobilization purposes.
