Hybrid polymer could be utilized for artificial muscles, drug delivery, self-repairing materials, and more

02/01/2016 - 16:20

Megan Fellman


Imagine a polymer with removable parts that can deliver something to the environment and then be chemically regenerated to function again. Or a polymer that can lift weights, contracting and expanding the way muscles do.

These functions require polymers with both rigid and soft nano-sized compartments with extremely different properties that are organized in specific ways.

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Ref: Simultaneous covalent and noncovalent hybrid polymerizations. Science (29 January 2016) | DOI: 10.1126/science.aad4091

ABSTRACT

Covalent and supramolecular polymers are two distinct forms of soft matter, composed of long chains of covalently and noncovalently linked structural units, respectively. We report a hybrid system formed by simultaneous covalent and supramolecular polymerizations of monomers. The process yields cylindrical fibers of uniform diameter that contain covalent and supramolecular compartments, a morphology not observed when the two polymers are formed independently. The covalent polymer has a rigid aromatic imine backbone with helicoidal conformation, and its alkylated peptide side chains are structurally identical to the monomer molecules of supramolecular polymers. In the hybrid system, covalent chains grow to higher average molar mass relative to chains formed via the same polymerization in the absence of a supramolecular compartment. The supramolecular compartments can be reversibly removed and re-formed to reconstitute the hybrid structure, suggesting soft materials with novel delivery or repair functions.