Scent properties by natural fragrance microencapsulation for footwear applications

Abstract

The aim of this study was to develop footwear materials and footwear packaging with scent properties using microencapsulated fragrances from essential oils. For that purpose, gelatine-carboxymethylcellulose (CMC) and melamine-formaldehyde (MF) resin-based microcapsules containing limonene were synthesised using complex coacervation and in situ polymerisation processes, respectively. The microcapsules were characterised using various experimental techniques and applied to footwear materials (leather and textile) as well as to paperboard as packaging material to evaluate their performance. The microcapsule durability under various conditions, such as rubbing and ironing, was analysed in order to simulate shoe manufacturing and shoe wearing conditions. The characterisation of the synthesised microcapsules showed two different delivery behaviours. On the one hand, MF microcapsules are more resistant so they may be incorporated into footwear materials that have to be exposed to high mechanical and thermal stresses, such as linings. On the other hand, gelatine-CMC microcapsules should be incorporated into footwear components, such as insoles, which are exposed to lower stresses because they are less resistant and might not resist the process conditions. The combination of both kinds of microcapsules could ensure a rapid as well as a long-lasting fragrance release.

Nanoencapsulation mechanism of fragrant oil: effect of formaldehyde − melamine molar ratio

“…Rigid thermal and mechanical tests demonstrated the durability of the melamine and formaldehyde. 20 The microcapsules obtained from the experiments showed thermal stability (Fig. 5) in comparison with non-encapsulated oil.…”

“…This group is stable at F / M ratios of 6 − 8 . Trimethylomelamine clusters exhibit a lower degree of polymerization than hexamethylamine clusters since they are less stable in water and mostly formed with low formaldehyde concentrations of between 2.5 and 4.5 …”

“…However, above this temperature, nanocapsules with F / M = 6 exhibited lower decomposition rates, unlike the thermal behaviour of the resin with F / M = 3 and 4 which showed considerable decomposition. Rigid thermal and mechanical tests demonstrated the durability of the melamine and formaldehyde …”

“…19 Trimethylomelamine clusters exhibit a lower degree of polymerization than hexamethylamine clusters since they are less stable in water and mostly formed with low formaldehyde concentrations of between 2.5 and 4.5. 20 Bands for C − O bonds, characteristic of the presence of ether bonds, are present in the resins and nanocapsules at 1150 and 1081 cm −1 . The spectra of the nanocapsules demonstrate that increased formaldehyde heightened the intensity of these bands in the resins.…”

Encapsulated Chlorhexidine Digluconate Usage on the Diabetic Footwear Lining Leathers

“…This technology allows heat, temperature or pH sensitive components to be physically enveloped in a protective matrix or wall material in order to protect these ingredients or core materials from adverse reactions, loss or against light, heat and prolonged contact with air. It is also one of the most important forms of controlled release of substances and allows the utilization of some that otherwise would be unfeasible (Nirmala, 2013;Sanchez-Navarro, 2015). These systems offer some advantages over conventional dosage forms, including improved efficiency, reduced toxicity and improved patient compliance (Grattard, 2002).…”