title: Use of a fractional factorial design to study the effects of experimental factors on the chitin deacetylation.
abstract: Chitosan is obtained by deacetylation of chitin. Chitosan versatility is directly related to the polymer's characteristics depending on the deacetylation process. The aim of this research was to study the parameters influencing deacetylation and to elucidate their effect on acetylation degree (DA) and molecular weight (MW). The effect on chitosan DA was investigated using a fractional factorial design 2(7-3) with seven factors and two variation levels. The tested factors were: X1=number of successive baths, X2=reaction time, X3=temperature, X4=alkali reagent, X5=sodium borohydride, X6=the atmospheric conditions and X7=alkali concentration. A mathematical model was investigated corresponding to the following relation ŷ=7.469-1.344X1-1.094X2-3.094X3+1.906X4+0.656X5+0.906X6-1.031X7+0.469X1X2-0.781X3X4+0.906X1X3X4 with R2=0.99. This model allows fixing experimental conditions for each desired DA. To study the effect on chitosan MW, only atmospheric conditions and use of sodium borohydride as an oxygen scavenger were investigated. The use of sodium borohydride and nitrogen atmosphere was found to have a protective effect against chitosan degradation during deacetylation.
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, National School of Engineering, PO Box 1173-3038, Sfax, Tunisia. Electronic address: islem.younes@gmail.com.
authors.forename: Islem
authors.initials: I
authors.lastname: Younes
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, National School of Engineering, PO Box 1173-3038, Sfax, Tunisia.
authors.forename: Olfa
authors.initials: O
authors.lastname: Ghorbel-Bellaaj
authors.affiliation: Laboratory of Industrial Chemistry, National School of Engineering, BP W 3038 Sfax, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Chaabouni
authors.affiliation: Biomaterials Applications, 6, rue Lesdiguières 38000 Grenoble, France.
authors.forename: Marguerite
authors.initials: M
authors.lastname: Rinaudo
authors.affiliation: Univ. Grenoble Alpes, DPM, F-38000 Grenoble, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Souard
authors.affiliation: CNRS, DPM, F-38000 Grenoble, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Vanhaverbeke
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, National School of Engineering, PO Box 1173-3038, Sfax, Tunisia.
authors.forename: Kemel
authors.initials: K
authors.lastname: Jellouli
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, National School of Engineering, PO Box 1173-3038, Sfax, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D000107:Acetylation; D002686:Chitin / Q000737:chemistry*; D048271:Chitosan / Q000378:metabolism; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular; D014783:Viscosity
chemical_list: D002686:Chitin; D048271:Chitosan
keywords: Acetylation degree; Chitin deacetylation; Molecular weight