The adsorption of acrylic polyampholytes on fiberglass reinforced plastics (FRP) was investigated using random copolymers derived from (dimethylamino)ethyl methacrylate (DM), methacrylic acid, and t-butyl methacrylate (t-BMA). The effect of the copolymer structure changes on the adsorption and the interactions between the copolymers and the surface were assessed using C-potential and contact angle measurements, NMR, and ESCA. The copolymer having the composition of 58 mol % pDM, 38 mol % pMMA, and 4 mol % pt-BMA was adsorbed on the FRP surface at pH 7, and it formed the highest hydrophilic surface among the tested copolymers. An analysis by use of atomic force microscope revealed that the copolymer afforded a uniform 4-6 nm thick coverage on the FRP. We concluded that the interactions between the copolymer's cationic sites and the anionic FRP surface are important as well as the hydrophobic interaction for adsorption. Furthermore, it is suggested that the hydrophilicity of the copolymer's adsorbed surfaces is related to the density of the copolymer's anionic sites. These results indicate that the ampholytic structure of the polymers would be essential for the surface modification on the FRP. The effect of functional groups of surfaces on the acrylate adsorption was also assessed using surface plasmon resonance. (c) 2006 Wiley Periodicals, Inc.