Effect of emulsifier on poly(urea–formaldehyde) microencapsulation of tetrachloroethylene

Microcapsules containing tetrachloroethylene as an internal phase were prepared by in situ polymerization of urea–formaldehyde (UF) without prepolymerization. The effects of different emulsifiers on the process of microencapsulation and morphology of microcapsules were investigated. The results show that the emulsifier gum arabic (GA) can effectively slow down the deposition rate of resin onto the oil/water interface, which can lead to smooth and compact surface of microcapsules. The surface activity of GA was also enhanced by complex formation of gum arabic and sodium dodecyl benzene sulfonate. The microcapsules represent good thermal and barrier property as a result of the formation of capsule wall with compact microstructure.