Modification of the diameter of microcapsules of poly (urea-formaldehyde) using octanol

ABSTRACT In self-healing polymers, capsules filled with healing agents are used, whose walls rupture as a response to external stimulation, releasing and sealing the cracks in the materials. Thus, this work had as objective to evaluate the possible changes in the morphology and diameter of microcapsules (MC) of poly(urea-formaldehyde) (PUF) by variation of the octanol concentration used in the synthesis. Through the measurements with optical microscopy (OM) and scanning electron microscopy with field effect (FEGSEM), it was verified that the MC diameter and the wall roughness associated with the formation of nanocapsules in the emulsion increased as the amount of octanol added in the synthesis increased. Thermal analysis showed that the microcapsules synthesized this way are more thermally stable compared to those reported in the literature. It was concluded that the use of octanol contributes to obtaining MCs with a more uniform size and smoother surface.