Microencapsulation of an insecticide by interfacial polymerisation

The objective of the work is to create a two-effect product composed by microcapsules containing insecticide suspended in concentrated disinfectant solution. A two-step microencapsulation process has been performed with a first step corresponding to the formation of an oil/water (o/w) dispersion in a static mixer and a second step to the microencapsulation by interfacial polymerisation in a stirred tank reactor. Microcapsules are characterized by a mean diameter of 30 gin in order to ensure their suspension in the disinfectant solution. Microcapsules wall is made of polyurea and release rates monitored by pH-measuring in the disinfectant solution, are found to be very low, allowing a good compatibility of insecticide and disinfectant. (C) 2002 Elsevier Science B.V. All rights reserved.