Microencapsulation of Bulky Multi Functional Reactive Isocyanates into Polyurethane Shell: Controlling the Microcapsules Size by Mixing Rate and Surfactant Concentration

In this study, polyurethane-based microcapsules containing bulky multi functional reactive isocyanates were synthesized using interfacial polymerization method in oil-in-water emulsion. The required materials for microcapsules preparation were synthesized via the reaction of trimethylolpropane (TMP) with either TDI and IPDI and the resulting products were used as the shell and core materials, respectively. FTIR spectroscopy was used for characterization of prepared chemicals. The effect of mixing speed and surfactant’s concentration on the size of the microcapsules was studied using optical microscopy and scanning electron microscopy (SEM). Investigation of recorded results confirmed dependence of microcapsules size to mixing speed and concentration of surfactant. The spherical microcapsules of 4-450μm in diameter and 1.88-4.10μm in wall thickness were obtained by changing mixing rate in the range of 500-850rpm and surfactant concentration in the initial aqueous feed in the range of 10-25%wt.

کلیدواژه ها:

Microencapsulation ، Reactive isocyanates ، Mixing rate ، Surfactant concentration