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Regioselective Grafting of Poly(ethylene glycol) onto Chitosan and the Properties of the Resulting Copolymers
Author(s) -
Liu Li,
Li Fangzhi,
Fang Yue'e,
Guo Shengrong
Publication year - 2006
Publication title -
macromolecular bioscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.924
H-Index - 105
eISSN - 1616-5195
pISSN - 1616-5187
DOI - 10.1002/mabi.200600087
Subject(s) - chitosan , copolymer , peg ratio , polymer chemistry , ethylene glycol , grafting , chemistry , chemical modification , thermal stability , aqueous solution , organic chemistry , polymer , finance , economics
Abstract Summary: PEG was grafted onto chitosan regioselectively at the hydroxyl groups with phthaloylchitosan as an intermediate. After the graft reaction, the phthaloyl groups were deprotected to give chitosan‐ g ‐PEG copolymers with free amino groups. The chemical structure of the graft copolymers was confirmed by FT‐IR, 1 H and 13 C NMR spectroscopy. The resulting graft copolymers showed improved thermal stability compared to the original chitosan, and showed a lower thermal transition temperature at around 185 °C. Chitosan‐ g ‐PEG exhibited a high affinity not only for aqueous acid but also for some organic solvents because of the presence of abundant free amino groups and PEG branches, and it exhibited higher hygroscopicity and moisture retention ability than chitosan.