Investigating the Effect of Surfactant Concentration in the Synthesis of Polyurethane Microcapsules Containing Isophorone Diisocyanate Healing Agent

In this study, preparation, characterization and the effect of surfactant concentration in the synthesis of polyurethane microcapsules have been investigated. At first, a pre-polymer was synthesized through the reaction of 2,4-toluene diisocyanate (TDI) and 1,4-butanediol in n-butyl acetate as solvent. The synthesized pre-polymer was characterized using Fourier transform infrared spectroscopy and free isocyanate content. Then polyurethane microcapsules were synthesized by interfacial polymerization based on the TDI-prepolymer and isophorone diisocyanate (IPDI), as the shell and core materials, respectively. Microcapsules were manufactured using different weight percentages of gum arabic as surfactant including 10,13 and 16 wt.%. Shape and surface morphology of microcapsules were studied using an optical microscope. The spherical microcapsules prepared in this study had a diameter of 40-200 μm.