Amphiphilic chemical additives are widely used to prevent the formation of asphaltene deposits and to promote demulsification of crude oil. Although it is known that the efficiency of these additives is mainly related to their structure and molar mass, this correlation is still not well established, because it is also related to the type of petroleum to be treated. In this work, C10I asphaltenes extracted from two different types of asphaltic residues were used to prepare model systems containing 1 wt % asphaltenes in toluene. Amphiphilic macromolecules, obtained from polymerization of cardanol by polyaddition and polycondensation, were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (H-1 NMR), and size-exclusion chromatography (SEC) and evaluated regarding their influence on the variation of asphaltene precipitation onset of model systems and the variation of volume and separation kinetics of water in model water-in-oil emulsions. The results show that the structure of polycardanol obtained by polyaddition favors its action as a dispersant of asphaltenes, which can be related to the fact that its phenol groups are relatively free to interact with the sites of the asphaltene molecules, as opposed to polymers obtained by polycondensation, in which the polymerization reaction occurs in the aromatic ring. Besides this, the demulsification results indicate a close relation of the dispersant action of this type of additive with its performance in water toluene separation, so that the separation kinetics is mainly related to the molar mass of the additive in determining the final performance. The results highlight potential asphaltene dispersants derived from renewable sources.