Aqueous Modification of Chitosan with Itaconic Acid to Produce Strong Oxygen Barrier Film.

Juho Antti Sirviö,Svitlana Filonenko,Anu M Kantola,Sanna Komulainen

doi:10.1021/acs.biomac.1c00216

Juho Antti Sirviö, Svitlana Filonenko + Show 2 more

Open Access

https://doi.org/10.1021/acs.biomac.1c00216

Copy DOI

Abstract

In this study, the chemical modification of chitosan using itaconic acid as a natural-based unsaturated dicarboxylic acid was investigated. In an aqueous environment, the amine group of chitosan reacts with itaconic acid to produce a chitosan derivative with pyrrolidone-4-carboxylic acid group. On the basis of the elemental analysis, 15% of the amine groups of chitosan reacted, thus creating modified chitosan with amine and carboxylic acid functionalities. Due to the presence of amine and carboxylic acid groups, the surface charge properties of the chitosan were notably altered after itaconic acid modification. In an aqueous solution, the modified chitosan exhibited zwitterionic properties, being cationic at low pH and turning anionic when the pH was increased over 6.5, whereas the original chitosan remained cationic until pH 9. Furthermore, it was demostrated that the modified chitosan was suitable for the preparation of a self-standing film with similarly high transparency but notably higher mechanical strength and oxygen barrier properties compared to a film made from the original chitosan. In addition, the thermal stability of the modified chitosan film was higher than that of the original chitosan film, and the modified chitosan exhibited flame-retardant properties.

Highlights

Natural-based materials and chemicals are currently desired as a replacement for the products derived from nonrenewable fossilbased resources
The chemical modification of chitosan was attempted in an aqueous itaconic acid solution
Due to the protonation of amine groups, chitosan dissolved in an itaconic acid solution during the reaction

Summary

Introduction

Natural-based materials and chemicals are currently desired as a replacement for the products derived from nonrenewable fossilbased resources. Replacing high-volume, single-use products, such as packaging as well as materials that end up in the environment, including soil stabilizers and water treatment chemicals, is of great interest due to the poor biodegradability and toxicity of fossil-based materials.[1]. Polysaccharides are a large family of sugar-based polymers, and they are widely available in many forms from renewable resources.[2] Among the most abundant polysaccharides are cellulose, starch, chitin, and chitosan. Cellulose and starch are glucose-based polymers available in plants as structural[3] and energy storage[4] components, respectively. Chitosan can be found in certain fungi.[6]

Methods

Results

Conclusion