Release of Fragrances from Polymer Coatings Triggered by Contact with Sweat

Fragrances are active compounds that suffer from the fact that fragrances are usually quickly volatile and hence display a limited use in daily life applications. To overcome this problem, the fragrances benzaldehyde and heptanal are conjugated to a monomer via a hydrazone linkage. The functional monomers are then reacted with a urethane acrylate by photopolymerization to yield thin polymer coatings. The release of fragrances from the coatings was measured by UV–visible spectroscopy and headspace gas chromatography–mass spectrometry techniques, showing sustained release in artificial sweat due to the slow kinetics of the hydrolysis of the hydrazone linkage. This simple strategy can be applied for the rapid preparation of coatings on contact with wet human skin in labeling applications.