A composition with improved adhesive and sealant properties comprises a) a pre-polymer comprising a polymeric unit of the general formula (-A-B-)n, wherein A represents a substituted or un-substituted ester, B represents a substituted or un-substituted acid ester comprising at least two acid ester functionalities, and n represents an integer greater than 1 wherein the content of grafted anhydride in the composition is less than 0.05mol/mol of polyacid.