Method for synthesising synthetic macromolecules or copolymers of the poly(alkoxyamine amide) type, in which the monomer type and the length of the monomer sequences are controlled, in which the monomer chain has at least one bond between monomers that is thermolabile, and in which the dissociation or separation temperature(s) is/are all greater than 30° C, preferably greater than 50° C, and more preferably greater than 60° C, but always less than 150° C, preferably always less than 130° C, characterised in that it consists in reacting, on a soluble or solid substrate, an acid monomer in the form of a monohalogenated carboxylic acid of formula X-C(R,R')-Y-COOH with an amine monomer that has a free terminal nitroxide >N-O ● free-radical group and a free terminal primary amine group -NH 2, by carrying out two chemically selective and separate chemical reactions: one consisting of reacting the aforementioned groups -COOH and -NH 2 in such a way as to obtain an amide bond -NH-CO-Y-C(R, R')-, and the other consisting of reacting the radical -Y-C(R, R') ●, obtained in situ using a catalyst adapted to said halogen element X, with said nitroxide >N-O ● group so as to obtain an alkoxyamine-type bond -Y-C(R, R')-O-N<, and repeating, alternately, said aforementioned chemical reactions as many times as necessary, in the presence of catalysts adapted to the element(s) X, with a new halogenated acid monomer of formula X-C(R, R')-Y-COOH that is identical to or different from the preceding halogenated acid monomers that are used or with a new free-radical amine monomer that has a free terminal >N-O ● group and a free terminal primary amine group -NH 2 that is identical to or different from the preceding free-radical amine monomers until the desired complete copolymer chain is obtained, method in which R is selected independently from the group that is formed by: H, CH 3, an alkyl group that has 2 to 6 carbon atoms, optionally substituted or polysubstituted; with R' being selected independently from the group that is formed by: H, CH 3, an alkyl group that has 2 to 6 carbon atoms, optionally substituted or polysubstituted; and Y being selected independently from the group formed by: Ø (covalent bond) and -COO-Z-, where Z is a hydrocarbon chain with 1 to 15 carbon atoms, linear, branched or cyclic, optionally substituted or polysubstituted, in particular by groups that are selected from the list that is formed by: -OH, -NH 2, -COOH, -CN, an alkyne group, in particular -C≡C-H, an alkene group, -N 3, -SO 3, with these groups being able to be protected by one or more suitable protective groups. H, CH 3, an alkyl group that has 2 to 6 carbon atoms, optionally substituted or polysubstituted; with R' being selected independently from the group that is formed by: H, CH 3, an alkyl group that has 2 to 6 carbon atoms, optionally substituted or polysubstituted; and Y being selected independently from the group formed by: Ø (covalent bond) and -COO-Z-, where Z is a hydrocarbon chain with 1 to 15 carbon atoms, linear, branched or cyclic, optionally substituted or polysubstituted, in particular by groups that are selected from the list that is formed by: -OH, -NH 2, -COOH, -CN, an alkyne group, in particular -C≡C-H, an alkene group, -N 3, -SO 3, with these groups being able to be protected by one or more suitable protective groups. H, CH 3, an alkyl group that has 2 to 6 carbon atoms, optionally substituted or polysubstituted; and Y being selected independently from the group formed by: Ø (covalent bond) and -COO-Z-, where Z is a hydrocarbon chain with 1 to 15 carbon atoms, linear, branched or cyclic, optionally substituted or polysubstituted, in particular by groups that are selected from the list that is formed by: -OH, -NH 2, -COOH, -CN, an alkyne group, in particular -C≡C-H, an alkene group, -N 3, -SO 3, with these groups being able to be protected by one or more suitable protective groups. Ø (covalent bond) and -COO-Z-, where Z is a hydrocarbon chain with 1 to 15 carbon atoms, linear, branched or cyclic, optionally substituted or polysubstituted, in particular by groups that are selected from the list that is formed by: -OH, -NH 2, -COOH, -CN, an alkyne group, in particular -C≡C-H, an alkene group, -N 3, -SO 3, with these groups being able to be protected by one or more suitable protective groups.