Preparation and Characterization of Polyurea Microcapsules Filled with Sulfur

Using sublimed sulfur as core material and polyurea as shell material,the polyurea microcapsules filled with sulfur were prepared by interfacial polymerization,and the effect of reaction time,molar ratio of ethylenediamine(EDA) and toluene-2,4-diisocyanate(TDI) on the microcapsule production,and influential factors of microcapsule coating rate were investigated.The results showed that,the reaction time and EDA/TDI molar ratio had little effect on the microcapsule production.The optimal reaction time was 2 h,and the optimal molar ratio of EDA/TDI was 1.5.The microcapsule coating rate was optimized when the mass fraction of gelatin was 0.03,addition level of emulsifier OP-10 was 0.5 g,mass ratio of water phase and oil phase was 1.2,and stirring speed was 200 r·min-1.The microcapsules were in regular form shown in SEM,and the thermal stability was good.