Gelatin extracted from chromium (III) tanned leather waste for the synthesis of controlled release hydrogel

Abstract

Chromium (III) tanned leather wastes were used to obtain gelatin, which was applied as a coating material for the synthesis of controlled urea release hydrogels. It was found that the hydrogel released its total urea content in 120 h in aqueous solution and that it promoted a significant difference in the growth of arugula seedlings. When compared with commercial gelatin, the hydrogels based on gelatin extracted from tannery waste had similar behavior, especially in the way urea was diffused to the external environment of the controlled release system, it can be characterized as a material of non-Fickian behavior during the swelling process and later, as a Fickian behavior, when it begins its process of degradation of the polymer matrix. In this way, this work demonstrates that it is possible to value a waste to obtain tools to promote a more sustainable agriculture.