Easy access to amphiphilic nitrogenous block copolymers via switchable catalysis

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Developing block copolymers from mixed monomers is challenging.
• Switchable polymerization catalysis offers a route to well-defined block copolymers.
• Current methods are limited to oxygenated monomers.

Purpose of the Study:

• To extend switchable polymerization to nitrogenous monomers.
• To synthesize amphiphilic nitrogenous block copolymers.
• To explore the potential of these copolymers in biomedicine.

Main Methods:

• Applied switchable polymerization to N-substituted N-carboxyanhydrides (NNCAs) and epoxides/cyclic anhydrides.
• Utilized density functional theory (DFT) for mechanistic insights.
• Employed nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), and in situ infrared (IR) spectroscopy for characterization.

Main Results:

• Successfully achieved copolymerization of NNCAs with epoxides and cyclic anhydrides.
• Synthesized amphiphilic polyester-block-polypeptoids with well-defined block structures.
• DFT calculations revealed thermodynamic favorability of cyclic anhydride reactions.

Conclusions:

• Switchable polymerization is now applicable to nitrogenous monomers, expanding synthetic possibilities.
• The synthesized nitrogenous block copolymers exhibit excellent anti-protein adsorption and low cytotoxicity.
• This strategy provides an efficient route to novel biomaterials.