Poly(acrylic acid)s of various molecular weights and different degree of hydrophobic modification have been synthesized by a polymer analogous reaction with tetradecylamine or copolymerization with styrene. Testing these amphiphilic polymers as stabilizers for the emulsion polymerization of styrene reveals that well stabilized latices are obtained within a certain range of molecular weight and hydrophobicity. As an example, the addition of 1 wt.-% polymer with respect to the monomer allows the synthesis of polystyrene latices with a radius of about 100 nm in the absence of ionic initiators or polar comonomers.