Polypeptoids: a model system to study the effect of monomer sequence on polymer properties and self-assembly

As the ability to control the monomer sequence of synthetic polymers increases, new relationships between sequence, polymer structure, and functional properties are being discovered. Recent advances in the sequence control of traditional copolymers, such as polyethylenes and polystyrenes, have led to well controlled primary structures ranging from periodic to more precise sequences. As a result, this unprecedented control in the chemical structure of the polymer has necessitated a reexamination of the role of monomer sequence on polymer properties, such as crystallization and self-assembly. In this review, we summarize the developments in establishing a relationship between a polymer's sequence and its properties, and we focus on one sequence-specific polymer system in particular: N-substituted glycines, or polypeptoids. Polypeptoid self-assembly has demonstrated remarkably tunable, hierarchical structures, and through this lens, we look to the future designability of sequence-specific polymers in general.