Polypropylene (PP) was modified through a peroxide-induced degradation and a catalytic hydrosilylation reaction in the melt phase. The effects of temperature and co-catalysts on the reaction and the surface characteristics of the hydrosilylated polypropylene (SiPP) were studied. Axisymmetric Drop Shape Analysis-Profile (ADSA-P) was used to characterize the sura cc wettability. The morphology, roughness and heterogeneity of the surface were investigated by the lateral force mode of atomic force microscopy (LFM). Proton nuclear magnetic resonance (H-1 NMR) spectroscopy was employed to quantify the conversion of terminal double bonds. X-ray photoelectron spectroscopy (XPS) was used to quantify the surface chemical composition. LFM images showed that the surfaces of the PP and DPP samples were rough but heterogeneous and that the surfaces of the SiPP samples appeared rough but homogeneous. The surface wettability was well correlated to the surface microstructure and surface chemical composition. The surfaces investigated were modeled based on the microstructure observed, and a new scheme was developed to calculate surface free energy and adhesion work. Results showed that there is an optimum reaction temperature in terms of the conversion of double bonds, and that increasing the amount of co-catalyst promotes the conversion.