The purpose of this work was to investigate the effects of polystyrene-based acidic copolymers and ionomers on the dispersion of asphaltenes in heavy oil. In the first part of the work, we studied the effect of the addition of sulfonated polystyrene acidic copolymers (SSA) and Na-neutralized ionomers (SSNa) on asphaltene dispersion. It was found that the SSA copolymers and the low ion content SSNa ionomers did not show asphaltene dispersion enhancement. However, high ion content SSNa ionomers improved asphaltene dispersion. In the second part of the work, styrene–methacrylate ionomers (SMANa) were used as dispersants. It was observed that the SMANa ionomers improved asphaltene dispersion significantly as the ion content increased and the molecular weight of the SMANa ionomer decreased. Finally, it was found that asphaltene dispersion was more effective when SMANa ionomers were used as asphaltene dispersants, compared to SSNa ionomers. Therefore, it can be concluded that to improve asphaltene dispersion, the acidic copolymers must first be converted to ionomers by neutralization. In addition, when using the ionomer as an asphaltene dispersant, it should be noted that the type of ionic group of the ionomer was more important to control asphaltene dispersion than the MW of the ionomer.

In this work, we studied the effects of storage moduli on thermal healing of poly(styrene‐co‐methacrylate) and poly(styrene‐co‐itaconate) ionomers. It was found that as the ion content and neutralization degree of the ionomers increased, the healing efficiencies decreased. This was due to the fact that the ionic aggregates, acting as physical cross‐links, and the clustered regions of the ionomers, reducing polymer chain mobility, interrupted the relaxation of the polymer chains near the damaged site, slowing the recovery. The most important finding in this work was that, to heal the ionomer without severe sample deformation, the optimal healing temperature should be the temperature where the storage modulus of the ionomer was similar to 106.6 Pa. Obviously, the healing rate and healing efficiency were mainly influenced by the healing temperature, related directly to the storage modulus of the polymer, and the maximum healing efficiency was strongly affected by healing time.