Synthesis of polymeric particles with insect repellent for potential application on textile substrates

This paper presents a process for producing particles loaded with the insect repellent ethyl butylacetylaminopropionate (IR3535®). The encapsulated particles were prepared via emulsification using monomers—2-hydroxyethyl methacrylate, methyl methacrylate, and sodium styrene sulfonate—and sodium persulfate—the initiator of the reaction—in an aqueous colloidal silica solution. The emulsion polymerization was carried out at 75 °C for 240 min without surfactants. The encapsulated materials were characterized by dynamic light scattering, electrophoretic mobility, scanning electron microscopy, Raman spectroscopy, and thermogravimetry. The encapsulated particles were in the submicrometric scale with an average diameter of 879 nm, moderate polydispersity index of approximately 0.5, and negative zeta potential. The encapsulation of 12.2% IR3535® was confirmed by high-performance liquid chromatography, demonstrating the efficacy of the encapsulated active material. The emulsion polymerization processes produced insect-repellent-carrying submicroparticles, thereby presenting a promising system for protection against mosquito bites with possible application to textiles.