The present invention provides a method for making a composition comprising anamphiphilic polymeric materialwhich comprises a straight or branched chain carbon-carbon backbone and amultiplicity of side chains attached to the backbone；wherein in the method, backbone precursors comprising acylating groups aremixed with side chain precursors which comprise anucleophilic group at at least one terminus, to form a reaction mixture； thebackbone precursors, side chain precursors and/or thereaction mixture are heated； the reaction mixture is stirred； and thenucleophilic groups react with the acylating groups to formthe amphiphilic polymeric materi al wherein the side chains are linked to thebackbone via acyl linkages； characterised in that thereaction mixture does not comprise organic solvent.
