Viscometric study of chitosan solutions in acetic acid/sodium acetate and acetic acid/sodium chloride

Abstract

A viscometric study was carried out at 25°C to assess the physical-chemical behavior in solution and the mean viscometric molar mass (M¯v) of chitosan solutions with different deacetylation degrees, in two solvent mixtures: medium 1-acetic acid 0.3mol/L and sodium acetate 0.2mol/L; and medium 2-acetic acid 0.1mol/L and sodium chloride 0.2mol/L. Different equations were employed, by graphical extrapolation, to calculate the intrinsic viscosities [η] and the viscometric constants, to reveal the solvent's quality: Huggins (H), Kraemer (K) and Schulz-Blaschke (SB). For single-point determination, the equations used were SB, Solomon-Ciuta (SC) and Deb-Chanterjee (DC), resulting in a faster form of analysis. The values of ̄M¯v were calculated by applying the equation of Mark-Houwink-Sakurada. The SB and SC equations were most suitable for single-point determination of [η] and ̄M¯v and the Schulz-Blachke constant (kSB), equal to 0.28, already utilized for various systems, can also be employed to analyze chitosan solutions under the conditions studied.

White-Rot Fungi Control on Populus spp. Wood by Pressure Treatments with Silver Nanoparticles, Chitosan Oligomers and Propolis

“…Chitosan oligomers of a viscosity-average MW of ca. 2000 Da were obtained [30] according to the experimental procedure proposed by Costa et al [36].…”

Effects of chitosan as growth promoter on diarrhea, nutrient apparent digestibility, fecal microbiota and immune response in weaned piglets

“…It is a natural product extracted from shrimp shells and has active amino and hydroxyl group, which contribute to its many biological activities. The deacetylation degree (DD) of CS was measured via acid-base titration (Yuan et al 2011) and its average molecular weight (Mw) was calculated via determination of intrinsic viscosity using the Mark-Houwink equation (Costa et al 2015). The DD of CS was approximately 85% and average Mw was 232 kDa.…”

Polysaccharide-based scaffold for tissue-regeneration

“…Chitin, discovered by Henri Braconnot in 1811, is an unbranched polysaccharide (glucose-based) broadly distributed in nature as the principal component of cell walls in fungi, exoskeletons of crustaceans, insects, arthropods, and other invertebrates [32]. The two biopolymers that composed chitosan (D-glucosamine and N-acetyl-D-glucosamine) are distinguishable from each other mainly by their solubility in acidic aqueous solutions [33]. When the degree of deacetylation of chitin reaches about 50%, it becomes soluble in aqueous acidic media and is how the chitosan becomes one [34].…”