Heterogeneous deacetylation reaction of chitin under low-frequency ultrasonic irradiation

Endarto Yudo Wardhono; Mekro Permana Pinem; Indar Kustiningsih; Mohammad Effendy; Danièle Clausse; Khashayar Saleh; Erwann Guénin

doi:10.1016/j.carbpol.2021.118180

Heterogeneous deacetylation reaction of chitin under low-frequency ultrasonic irradiation

Carbohydr Polym. 2021 Sep 1:267:118180. doi: 10.1016/j.carbpol.2021.118180. Epub 2021 May 11.

Authors

Endarto Yudo Wardhono¹, Mekro Permana Pinem², Indar Kustiningsih³, Mohammad Effendy⁴, Danièle Clausse⁵, Khashayar Saleh⁵, Erwann Guénin⁵

Affiliations

¹ Chemical Engineering Department, University of Sultan Ageng Tirtayasa, Jl. Jendral Sudirman Km 3, Cilegon 42435, Indonesia. Electronic address: endarto.wardhono@untirta.ac.id.
² Chemical Engineering Department, University of Sultan Ageng Tirtayasa, Jl. Jendral Sudirman Km 3, Cilegon 42435, Indonesia; Integrated Transformations of Renewable Matter Laboratory, Sorbonne Universités, Université de Technologie de Compiègne, rue du Dr Schweitzer, 60200 Compiègne, France.
³ Chemical Engineering Department, University of Sultan Ageng Tirtayasa, Jl. Jendral Sudirman Km 3, Cilegon 42435, Indonesia.
⁴ Mechanical Engineering Department, Universitas Negeri Surabaya, Surabaya, Indonesia.
⁵ Integrated Transformations of Renewable Matter Laboratory, Sorbonne Universités, Université de Technologie de Compiègne, rue du Dr Schweitzer, 60200 Compiègne, France.

PMID: 34119148
DOI: 10.1016/j.carbpol.2021.118180

Abstract

Low-frequency ultrasonic irradiation was employed as a low cost technique for chitin's deacetylation at a relatively low-temperature range (below 70 °C) and a short reaction times (up to 120 min). Eley-Rideal mechanism and the power-law model were carried out to describe the mechanism of the reaction. The results indicated that the produced chitosan deacetylation degree (DD) was up to 87.73% under the optimum conditions compared to 66.82% using the conventional one (thermo-alkaline process). The Fourier Transform Infrared (FTIR) observations of the produced chitosan presented the same fingerprint as the commercial chitosan, X-Ray Diffraction (XRD), and Differential Scanning Calorimetry (DSC) studies show that the DD induced a lousy impact on the chitosan's thermal degradation and crystallinity index. This work effectively demonstrates that chitin's deacetylation under low-frequency ultrasonic irradiation provides a green process to produce chitosan, and the power-law model, r_DD = k₁(C_R1-NH2)^α; k₁=Aexp-E_aRT, is an excellent model to describe the complex reaction.

Keywords: Chitin; Chitosan; Deacetylation; Degree of deacetylation; Power-law model; Ultrasonic treatment.