Designing nanoporosity in a swollen polymer for the controlled release of a highly volatile fragrance

Controlling the fragrance release profile, especially the highly volatile top note, can prolong the desired scent of the fragrance. Here, the porosity of a swollen cross‐linked polyurethane acrylate (PUA) polymer, which is tuned by the length of a modulator, can influence the evaporation rate of the top note. In particular, the evaporation rate of benzyl acetate (BA), a common top note, is reduced by a factor of 6.5 (from 134 to 17 mg m–2 min–1) when BA is released from the best‐performing PUA against a reservoir of BA. The average diameter of an opening in the fragrance‐loaded PUA is ~6 nm, as determined by the thermoporosimetry approach. Such a pore size can effectively control the evaporation rate of BA, as predicted by the theoretical model, which reveals that a pore diameter of