ENCAPSULATION PROCESS IN SYNTHESIZING POLYUREA MICROCAPSULES CONTAINING PESTICIDE

Polyurea microcapsules containing pesticide (Dursban trade name for 0,0- 3,5,6-trichloro-2-pyfidyl phosphorothioate, C91-I11C13NO5PS) as an active agent were prepared by reaction of polyisocyanate (such as toluene diisocyanate) and polyamine (such as diethylene triamine) as the monomers . The first step gives rise to the formation of oil-in-water emulsion, this is followed by initiation of polymerizationprocess to produce polyurea capsule wall . It has been found that the microcapsule formation depends on temperature, type and amount of emulsifier, co-emulsifier, matrix forming agent, stirring speed, organic phase, eta This paper is devoted to the studies of above factors that optimize the formation of microcapsules wall . Formation of polyurea was confirmed by FTIR technique and the thermal behaviour of polyurea microcapsules was investigated by differential scanning calorimeter)/ method . The morphology of microcapsules was studied by scanning electron microscope.