Kategorie: ‘Chitosan’
New publication:
Gentle dissolution of chitosan
Despite its very low pKa value, hydrochloric acid is one of the most commonly used acids in the production of chitosan hydrogels for biomedical applications. Although hydrochloric acid is widely used, the occurrence of unwanted depolymerisation in the production of hydrogels from chitosan hydrogels is often disregarded. In order to fully exploit the potential of chitosan as a renewable resource, a new, very mild method for the preparation of chitosan solutions is described here.
These solutions dry to clear, transparent films that remain completely water soluble and absorb up to 70 wt% water from the water in the 90 % RH vapour phase at 25 °C. Absorption follows simple first-order kinetics and the rate constants The rate constants increase with increasing humidity up to about 71 % RH, where a metastable chitosan trihydrate salt appears to be formed. Desorption is slightly faster, but more complex, as it involves two different first-order processes. In addition, the films produced in this way are thermally more stable than the usual chitosan hydrochloride.
M. B. Endres, O. Weichold
Sorption-active transparent films based on chitosan
Carbohydrate Polym. 2019, 208, 108–114. https://doi.org/10.1016/j.carbpol.2018.12.031
