Scent properties by natural fragrance microencapsulation for footwear applications

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. (c) 2015 Society of Chemical Industry