The invention relates to a copolymer having a controlled structure, comprising at least two parts, part A and part B, said parts having different compositions, wherein part A is a hydrophilic or hydrophobic part, and part B is a part comprising units deriving from a monomer B having formula: CH2=CR CO-[O-(CH2)p-]nOR or CH2=CR CO-[O-CH2-a(CH3)a- CH2-b(CH3)b-]nOR , wherein R is hydrogen or a methyl group, p, which is identical or different, is 2 or 3, a, which is identical or different, is 0 or 1, b, which is identical or different, is 0 or 1, a+b=0 or 1, p=2+a+b, n is an average number being greater than or equal to 1, and R is an alkyl group. The inventions also relates to the use of the copolymer or to compositions or formulations comprising the copolymer.