To date, scalability limitations have hindered the exploration and application of sequence-defined polymers in areas such as synthetic plastics, fibers, rubbers, coatings, and composites. Additionally, the impact of sequence on the properties of cross-linked networks remains largely unknown. To address the need for synthetic methods to generate sequence-defined materials in gram quantities, we developed a strategy involving inexpensive and readily functional vanillin-based monomers to assemble sequence-defined polyurethane oligomers via sequential reductive amination and carbamation. Three oligomers were synthesized with monomer sequence precisely dictated by the placement of reactive side chains during the reductive amination reaction. Avoiding excessive chromatographic purification and solid- or liquid-phase supports enabled synthesis of sequence-defined oligomers on the gram-scale. Remarkably, sequence was shown to influence network topology upon cross-linking, as evidenced by sequence-dependent rubbery moduli values. This work provides one of the first examples of a scalable synthetic route toward sequence-defined thermosets that exhibit sequence-dependent properties.
Bibliographical noteFunding Information:
Financial support for E.H., C.M., and C.A. was provided by the Army Research Office under award number W911NF-15-10179. Support for G.D.H. and M.H. was provided by the Center for Sustainable Polymers under award number CHE-1413862. G.D.H. also acknowledges the University of Minnesota Doctoral Dissertation Fellowship. This work made use of the Cornell University NMR Facility, which is supported, in part, by the NSF under award number CHE-1531632. The authors thank the Coates group for access to their DSC.
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PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.