Preparation and characterization of microcapsule-containing self-healing asphalt

Microcapsules-loaded with healing agent were successfully prepared in which dimethylphenol(DMP) or SBS/DMP forms core while urea/formaldehyde resin constitutes shell of the microcapsule. Microcapsule-containing asphalts displayed better mechanical properties than non-contained ones. The impact strength of microcapsule-containing asphalts improved over time. Microcapsule(DMP)-containing asphalt needed 7 days of rest time to restore its original strength, but it took only 3 days for microcapsule(SBS/DMP)-containing asphalt. This tells that microcapsule(DMP or SBS/DMP) containing asphalt posses excellent self-healing potential. SEM and X-ray photos illustrate that DMP on the asphalt fracture surface, which burst out of the microcapsules when cracks occur on the surface of the asphalt, undergoes polymerization to poly(phenylene oxide), filling cracks and healing damage.