Amphiphilic triblock copolymers B-A-B, wherein A is a linear poly(ethylene glycol) block, having a number average molecular weight (Mn) of between 900 and 3000 Daltons, determined with size exclusion chromatography wherein B are hydrophobic blocks with at least two cyclic monomers selected from the group consisting of glycolide, lactide, 1,3-dioxan-2-one, 5,5-dimethyl-1,3-dioxan-2-one, 1,4-dioxan-2-one, 1,4-dioxepan-2-one, 1,5-dioxepan-2-one, each B-block having a number average molecular weight (Mn) of between 400 and 2000 Daltons, determined with size exclusion chromatography and wherein 25% to 100% of the polymer hydroxyl end-groups are covalently modified with at least one derivative of a C2-C20 fatty acid. The invention also relates to compositions with such polymers and the use thereof.
