Microencapsulação de óleo essencial de citronela em resina de poli (Benzoguanamina-formaldeído)

Abstract

The development of essential oil microencapsulation systems has been widely explored for retention and release of aromas. However, research shows that microencapsulation yields are still low. Therefore, the search for technologies that allow obtaining better yield of encapsulated volatile oils is necessary. The present work deals with the preparation and characterization of polymeric microcapsules of poly (benzoguanamine-formaldehyde), containing the essential oil of citronella, which is mainly used as a repellent of mosquito vector diseases such as dengue, chikungunya, zika virus and malaria, used as core material. Using in situ polymerization via emulsion, six batches of microcapsules were prepared, varying process parameters such as stirring speed and essential oil concentration. The microcapsules prepared without and with oil were characterized by optical microscopy, thermogravimetric analysis (TGA), laser diffraction (DL), gas chromatography coupled to mass spectrometer (GC/MS) and infrared spectroscopy (IV). The results revealed that the process parameters influenced the diameter of the microcapsules, which ranged between (2.1 ± 0.3) μm and (38 ± 0.4) μm. The research showed an excellent result in terms of encapsulation efficiency, with amounts of up to 60% of essential oil in relation to the polymer (% m/m) and with efficiency of up to (96 ± 2) %. The microcapsules presented an excellent performance in the retention of the essential oil, being possible to maintain it for three months or more, indicating that there is a low permeability of the polymer membrane.