The use of a compound having the following formula: in which: - A 1 represents a divalent alkylene radical, which is linear or branched, comprising from 2 to 20 carbon atoms, preferably from 5 to 18, and preferably from 6 to 17, the said radical possibly comprising one or more unsaturations, and being possibly substituted by at least one substituent - OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; - A 2 represents a divalent alkylene radical, which is linear or branched, comprising from 2 to 20 carbon atoms, preferably from 2 to 12, and preferentially from 2 to 10, the said radical possibly comprising one or more unsaturations, and being possibly substituted by at least one substituent - OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; - A 3 is selected from the group consisting of the following divalent radicals: ∘ a linear or branched alkylene, comprising from 2 to 600 carbon atoms, preferably from 2 to 400, and preferentially from 2 to 100, the said radical possibly comprising one or more unsaturations, being possibly interrupted by at least one heteroatom selected from O, N and S, and being possibly substituted by at least one substituent -OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; and ∘ an arylene comprising from 6 to 30 carbon atoms, the said radical being possibly substituted by at least one substituent -OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; - X 1, X 3 and X 4, which may be identical or different, represent, independently of one another, -O- or -NH-; - X' 2 is selected from the group consisting of: -S-, -CH 2 - and a bond; and - n and m represent, independently of one another, an integer ranging from 1 to 1000, preferably from 1 to 100, and preferentially from 1 to 50; on the condition that the total number of carbon atoms of the radicals A 1, A 2 and X' 2 is greater than or equal to 8, preferably greater than or equal to 10; for the preparation of additives in a matrix of polyester, poly(vinyl chloride), polyurethane, polyamide, poly(alkyl acrylate), poly(alkyl methacrylate), polystyrene or polyolefin. - A 1 represents a divalent alkylene radical, which is linear or branched, comprising from 2 to 20 carbon atoms, preferably from 5 to 18, and preferably from 6 to 17, the said radical possibly comprising one or more unsaturations, and being possibly substituted by at least one substituent - OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; - A 2 represents a divalent alkylene radical, which is linear or branched, comprising from 2 to 20 carbon atoms, preferably from 2 to 12, and preferentially from 2 to 10, the said radical possibly comprising one or more unsaturations, and being possibly substituted by at least one substituent - OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; - A 3 is selected from the group consisting of the following divalent radicals: ∘ a linear or branched alkylene, comprising from 2 to 600 carbon atoms, preferably from 2 to 400, and preferentially from 2 to 100, the said radical possibly comprising one or more unsaturations, being possibly interrupted by at least one heteroatom selected from O, N and S, and being possibly substituted by at least one substituent -OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; and ∘ an arylene comprising from 6 to 30 carbon atoms, the said radical being possibly substituted by at least one substituent -OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; ∘ a linear or branched alkylene, comprising from 2 to 600 carbon atoms, preferably from 2 to 400, and preferentially from 2 to 100, the said radical possibly comprising one or more unsaturations, being possibly interrupted by at least one heteroatom selected from O, N and S, and being possibly substituted by at least one substituent -OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; and ∘ an arylene comprising from 6 to 30 carbon atoms, the said radical being possibly substituted by at least one substituent -OAlk, Alk representing an alkyl group comprising from 1 to 10 carbon atoms; - X 1, X 3 and X 4, which may be identical or different, represent, independently of one another, -O- or -NH-; - X' 2 is selected from the group consisting of: -S-, -CH 2 - and a bond; and - n and m represent, independently of one another, an integer ranging from 1 to 1000, preferably from 1 to 100, and preferentially from 1 to 50;