International.
A group of international researchers prepared a shape memory composite (SMC) coating with a self-healing capacity, using a method based on a thermosensitive shape memory (SMP) polymer that uses carnauba wax microparticles as a healing agent.
Damage to the SMC coating layer was healed by heating, which triggers a two-stage healing mechanism that involves closing the defect by a shape memory effect at 65 °C and then sealing the defects with molten wax at 90 °C.
The surface morphologies of the striped and cured coatings as well as a wax-free SMP coating were first studied by scanning electron microscopy and stereoscopic optical microscopy (SEM).
To determine the recovery of coating barrier properties, macroscopic and localized information was obtained by electrochemical impedance spectroscopy (EIS) and electrochemical scanning microscopy (SECM), respectively. Healing performance was also assessed by comparing the macroscopic morphologies of intact, damaged and cured coatings after long-term immersion.
The results of both tests agreed and confirmed the main functions of carnauba wax microparticles in the complete recovery of the barrier properties of initially damaged coatings after thermally assisted self-healing.
Source: Progress in Organic Coatings
