Functional properties of chitosan films with conjugated or incorporated salicylic acid

The aim of this work to find out the influence of salicylic acid-grafted-chitosan (SA-g-CS) and salicylic acid incorporated chitosan on the properties of chitosan film. The SA-g-CS conjugated films (SA-g-CS., SA-g-CS., and SA-g-CS.) and the SA-CS incorporated films (SA-CS., SA-CS., and SA-CS.) with equivalent salicylic acid content were prepared, respectively. The physical, mechanical, and biological properties of SA-g-CS conjugated and SA-CS incorporated films were evaluated. The opacity and water solubility were enhanced, thickness and water vapor permeability changed, and moisture content, tensile strength and elongation at break of chitosan film decreased or increased after conjugation or incorporation of SA. Compared with CS film, SA-g-CS conjugated and SA-CS incorporated films showed enhanced antioxidant and antibacterial activities, and these activities increased with the increasing of SA content. SA-g-CS conjugated films possessed better water vapor barrier property, antioxidant and antibacterial properties than SA-CS incorporated films. Therefore, SA-g-CS conjugated films exhibited better functional properties than SA-CS incorporated films. Compared with incorporation, conjugation of SA with CS is a more efficient way to improve properties of CS film. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study demonstrates that salicylic acid grafting and salicylic acid incorporation have significant effects on the properties of chitosan film, with salicylic acid grafted films showing better functional properties. Compared with salicylic acid incorporation, salicylic acid grafting is a more efficient way to improve the properties of chitosan film.