Hybrid molecular brushes (HMB) are macromolecular constructs consisting of a polymer backbone with side chains with different nature and properties. In this study, HMB composed of polylactide (PLA) and polyacrylamide (PAAm) immobilized on chitosan (CHI) backbone was synthesized. First, grafting of PLA on CHI was performed by ring opening polymerization (ROP) of lactide at room temperature. Methanesulfonic acid and 4-dimethylaminopyridine acted as organocatalysts. Hydroxyl of CHI acted as initiators. ROP was carried out in biphasic system as there is no common solvent for CHI and PLA. This composition allowed us to control the CHI chain degradation. Chemical grafting of PLA on CHI was proven by FTIR and NMR. Chain length and grafting density was estimated by gel permeation chromatography and atomic force microscopy. The product CHI<i>-g</i>-PLA was soluble in polar organic solvents. Grafting of secondary polymer PAAm was done in the course of radical polymerization of acrylamide in emulsion. Amino groups of CHI activated by ammonium persulfate served as initiating sites. The resulting HMB was characterized by atomic force microscopy and dynamic light scattering. HMB may find applications in surface and solubility modifications, as emulsifying agents, wound healing and tissue engineering.

Synthesis of hybrid molecular brushes with chitosan backbone in biphasic reaction

251st National Meeting (2016)

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