Copolymer with surfactant blocks prepared by controlled free radical polymerisation

The invention concerns a copolymer with surfactant blocks comprising at least a hydrophilic block and at least a hydrophobic block prepared by a preparation method called living or controlled method, said copolymer having a number molecular weight ranging between 1000 and 50000, preferably between 2000 and 20000, more preferably still between 4000 and 16000, a glass transition temperature of the hydrophobic block less than 30 DEG C, preferably less than 25 DEG C and higher than -100 DEG C, a surface tension less than 60 millinewton per meter (mN/m), preferably less than 50 mN/n measured at a concentration in demineralized water not more than 10<-4> mole/l, and the transfer agent having been made inert relative to said free radical polymerisation. The copolymers are useful in particular in detergents, paints, adhesives and building materials.