Functional textiles are being developed in order to provide fabrics with new properties and added value. They can be obtained either by using new chemical fibers or by incorporating functional agents to conventional fabrics. Microencapsulation is an effective method to protect these functional agents from reactions with moisture, light, and oxygen. If a fabric is treated with microencapsulated functional agents, higher durability of functionality is expected. This article reports the development and testing of two types of microcapsules containing essential oils for application in cotton fabrics. Microcapsules were obtained by complex coacervation using gelatin and arabic gum or by encapsulation in yeast cells in order to increase the durability of fragrances in textiles. Microcapsule characterization, such as particle size and morphology, was carried out for different oils to polymer ratios and hardening agents to polymer ratios. Padding and coating were tested as application methods. The morphology, durability of the fragrance, and laundering properties of the treated fabrics were investigated. The use of an electronic nose to measure the fragrance release from microcapsules was also evaluated. Gelatin—arabic gum microcapsules increased the durability of the fragrance on the treated fabrics and withstood one wash cycle. Fabrics treated with yeast cell microcapsules presented low fragrance intensity before washing. The fragrance was not detectable after laundering, even though the microcapsules could still be observed on the fabric.

Micro and nanocomposites of hydroxyl terminated polybutadiene (HTPB)-based polyurethanes (NPU) were obtained using five mineral fillers and Cloisite 20A nanoclay, respectively. Samples were prepared by the reaction of HTPB polyol and toluene diisocyanate (TDI), and the chain was further extended with glyceryl monoricinoleate to produce the final elastomeric polyurethanes. Mechanical and thermal properties were studied, showing that mineral fillers (20% w/w) significantly increased tensile strength, in particular nanoclay (at 5% w/w). When nanoclay-polymer dispersion was modified with a silane and hydantoin-bond promoter, elongation at break was significantly increased with respect to NPU with C20A. Thermal properties measured by differential scanning calorimetry (DSC) were not significantly affected in any case. The molecular structure of prepared micro and nanocomposites was confirmed by Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Interaction of fillers with polymer chains is discussed, considering the role of silanes in compatibilization of hydrophilic mineral fillers and hydrophobic polymer. The functionalization of nanoclay with HMDS silane was confirmed using FTIR. Microstructure of NPU with C20A nanoclay was confirmed by Atomic Force Microscopy (AFM).

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