Preparation of polyurea microcapsules containing ovalbumin

Polyurea microcapsules containing a hydrophilic protein, ovalbumin were prepared by the reaction of toluene diisocyanate (TDI) with ethylene diamine (EDA), hexamethylene diamine (HDA), and water-borne diamine, and their characteristics were investigated for the wall structures, thermal properties, and morphologies. The microcapsules from EDA had the strongest intensity of -NH to -CH, showing production of the strongest wall membrane, while the intensity of microcapsules from HDA significantly decreased due to the relatively long methylene chain. From thermal analysis, it was concluded that polyurea microcapsules prepared in this study had thermal stability with endothermal peaks at 280 similar to 350 degrees C. (C) 2000 Elsevier Science S.A. All rights reserved.