Highly efficient room temperature grafting polymerization of cellulose for the synthesis of cellulose-g-polypeptide biological macromolecules.

Cellulose, a widely abundant polysaccharide, constitutes over 50 % of the carbon content in the plant kingdom. The grafting polymerization of cellulose is a specialized technique that can significantly enhances the utility of this biopolymer. However, conventional polymerization methods for cellulose grafting, such as radical polymerizations of vinyl compounds and ring-opening polymerizations (ROPs) of cyclic esters, often require harsh conditions, including elevated temperatures and the use of metal complexes, strong bases, or strong acids as catalysts. This study aims to develop a highly efficient room temperature grafting polymerization method for cellulose modification, utilizing organocatalytic ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCAs). In contrast to traditional polymerization techniques, the ROP of NCAs demonstrates high activity and selectivity at ambient temperature. A diverse array of cellulose-graft-polypeptide copolymers was successfully synthesized under mild conditions using various cellulose substrates, including hydroxyethyl cellulose (HEC), microcrystalline cellulose (MCC), and cellulose paper. The integration of cellulose with polypeptides that exhibit structural similarities to natural peptides and proteins can enhance the biodegradability and biocompatibility of cellulose, broadening its potential applications in the life sciences sector.