Self-repair of structural and functional composites with intrinsically self-healing polymer matrices: A review

Abstract

Self-healing is a smart and promising way to make materials more reliable and longer lasting. In the case of structural or functional composites based on a polymer matrix, very often mechanical damage in the polymer matrix or debonding at the matrix-filler interface is responsible for the decrease in intended properties. This review describes the healing behavior in structural and functional polymer composites with a so-called intrinsically self-healing polymer as the continuous matrix. A clear similarity in the healing of structural and functional properties is demonstrated which can ultimately lead to the design of polymer composites that autonomously restore multiple properties using the same self-healing mechanism.

Self-Healing and Damage Resilience for Soft Robotics: A Review

“…Also, hydrogel composites tend to have higher resistances (greater than 1 kΩ for small samples), limiting their use to mostly strain sensing rather than conductive pathways. For a more comprehensive look at self-healing composite polymers (both bulk composites and conductive composites), readers are referred to these other recent, in-depth reviews/book chapters: Gibson (2010), Benight et al (2013), Zhu et al (2014), Ahner et al (2015), Zhong and Post (2015), .…”

Using feedback control to actively regulate the healing rate of a self-healing process subjected to low cycle dynamic stress

“…This current is proportional to the deposition rate and can easily be measured during experiment. The minimum voltage that is required from the electromechanical material to actuate the electrolysis process is expressed in (13).…”

“…One way to overcome high viscosity is to increase the temperature and choose healing agents with low viscosity. Overall, intrinsic self-healing is generally restricted to a small damage zone [13] and as such has limited applications. Also, a trigger which most of the time is externally supplied, is required to initiate healing and does not necessarily make this approach autonomous.…”

“…The self-healed polymer showed improved tensile and compressive strength when compared with damaged polymer. In an attempt to reduce the high energy limitation of a thermally reversible reaction, a moderately driven thermal approach using disulphide chemistry during covalent bonding to mend the damaged area was presented [13]. Another method of intrinsic self-healing is to use thermoplastic as the healing agent, which is initiated in a polymeric composite material by heat.…”

“…The potential of such materials is that they can be used as actuators and sensors. Polymers currently used that exhibit such characteristics are Lead Zirconate Titanate (PZT), poly vinylidene fluoride (PVDF) and dielectric elastomers [13,37]. Two studies prepared poly vinylidene fluoride-cohexafluropropylene (PVDF-HFP) solid electrolyte by mixing PVDF-HFP, zinc oxide and copper nanoparticles together [6,38].…”