Chemical modification of chitosan under high-intensity ultrasound and properties of chitosan derivatives

Chitosan (CTS), a biocompatible, biodegradable, nontoxic polymer, shows poor affinity for organic solvents. A novel chitosan derivative carrying the p-acetamidobenzoylate group was synthesized by the acylation reaction of chitosan with p-acetamidobenzoylate chloride in an acetic acid system under high-intensity ultrasound. The maximum substitution degree of the derivative was 0.42. The structure of the p-acetamidobenzoylate chitosan was characterized by FT-IR spectrometry, UV spectrometry and elemental analysis. The UV results showed that the derivative had good ultraviolet absorption at 273 nm. The solubility of the derivative was higher than that of chitosan. Taking advantage of the known capacity of solubility and ultraviolet absorption, the new derivative opens new possibilities for use as a sunscreen.