Nonylphenol ethoxylated (NPE) additives were melt blended in polypropylene (PP) films and characteristics of the modified films were investigated. It was found that melt blending of NPE additives improved hydrophilicity of PP films through additive surface segregation. Surface specific techniques, such as X-ray photoelectron spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) were used to study surface compositions of samples modified with NPE additives at different aging time after extrusion. We found that surface enrichment of additives lead to hydrophilic surfaces. Hydrophilic chain length in NPE affected surface composition and hydrophilicity of NPE containing PP polymer. The effect of water immersion and aging were also reported. POLYM. ENG. SCI., 52:19201927, 2012. (c) 2012 Society of Plastics Engineers