The present invention relates to the field of perfumery. More particularly, it concerns polymers derived from siloxane derivatives and comprising at least one β-thio carbonyl moiety capable of liberating an active molecule such as, for example, an α,β-unsaturated ketone or aldehyde. The present invention concerns also the use of polymers in perfumery as part of a perfuming or malodor counteracting composition as well as the perfuming compositions or perfumed articles comprising the invention's compounds.