Ionic and covalent crosslinking in chitosan-succinic acid membranes: Effect on physicochemical properties

Francesco Gabriele; Anna Donnadio; Mario Casciola; Raimondo Germani; Nicoletta Spreti

doi:10.1016/j.carbpol.2020.117106

Ionic and covalent crosslinking in chitosan-succinic acid membranes: Effect on physicochemical properties

Carbohydr Polym. 2021 Jan 1:251:117106. doi: 10.1016/j.carbpol.2020.117106. Epub 2020 Sep 17.

Authors

Francesco Gabriele¹, Anna Donnadio², Mario Casciola³, Raimondo Germani³, Nicoletta Spreti⁴

Affiliations

¹ Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio, I-67100 Coppito, L'Aquila, Italy.
² Department of Pharmaceutical Sciences, University of Perugia, Via del Liceo, 1, 06123 Perugia, Italy.
³ CEMIN, Centre of Excellence on Nanostructured Innovative Materials, Department of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 8, I-06123 Perugia, Italy.
⁴ Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio, I-67100 Coppito, L'Aquila, Italy. Electronic address: nicoletta.spreti@univaq.it.

PMID: 33142643
DOI: 10.1016/j.carbpol.2020.117106

Abstract

In this work, chitosan-succinic acid membranes were prepared by casting method and the physicochemical and mechanical properties of non-neutralized and neutralized with NaOH films were compared. Mechanical strength, flexibility, thermal stability and water-vapor permeability of chitosan membranes are significantly improved after neutralization. These improvements could be partly ascribed to the use of a dicarboxylic acid, which decreases the spacing between chitosan chains as a consequence of ionic crosslinking. Moreover, the addition of the strong base to the hydrogel promotes the formation of amide bonds, as suggested by FTIR analysis and demonstrated by acid-base titration. The favorable features of chitosan-succinic acid films as well as the possibility to easily incorporate drugs, enzymes, essential oils or other additives in the hydrogel, make such membranes suitable for many applications.

Keywords: Amide bonds; Chitosan films; Neutralization; Succinic acid.