Advances in self-healing polymers and composites

Press release

A major critical review covering the latest developments in self-healing polymers and composites has recently appeared as an open access article in International Materials Reviews. Authored by leading authority Mike Kessler and Tim Mauldin of Iowa State University, the review surveys the systems developed to allow self-healing and the progress in implementing these systems in real applications.

Realising the full potential of polymer composites in critical applications such as aircraft structures requires an improved understanding of damage and failure mechanisms in these materials and effective means of avoiding or mitigating damage and degradation. An approach that has attracted much attention in recent years is to design materials systems capable of autonomous repair, the aim being effectively to eliminate the possibility of catastrophic failure and, by reducing the need for monitoring and human intervention, reduce maintenance costs.

Attempts to design self-repairing systems have drawn inspiration from natural processes, particularly wound healing processes in biological systems. Several synthetic polymer systems have been developed that can repair themselves with complete, or nearly complete, autonomy. A major critical review of recent developments in this area has been published by Mike Kessler and Tim Mauldin of the Polymer Composites Research Group at Iowa State University in the journal International Materials Reviews. Published under the journals MORE OpenChoice option, the review is open access to all readers.

Professor Kessler has worked in this rapidly expanding field for more than a decade and was a co-author of a seminal paper on self-repairing polymers published in Nature in 2001. His current work focuses on self-healing biorenewable polymers that offer alternatives to petroleum based resins.

The review surveys first the major successful autonomic repairing mechanisms developed over the past decade. These include crack filling by healing agents delivered via microcapsules or hollow fibres and activated by catalysts or by phase separated healing agents. Here, the healing agent is released by the deformation associated with crack growth and forms three-dimensional polymer chains that fill the crack. Another approach employs molecular diffusion of a mobile species to create chemical or physical adhesive linkages or the unique class of ‘mendomer’ materials that have specific reversible bonds capable of producing repeated healing under thermal or ultraviolet stimulus. Localised strengthening mechanisms activated by stress are also covered.

Issues related to transferring these self-healing technologies from the laboratory to real applications are also reviewed. These issues include virgin polymer property changes as a result of the added healing functionality, healing in thin films versus bulk polymers, and healing in the presence of structural reinforcements. The fact that products utilising self-healing mechanisms are beginning to enter the market in significant quantities speaks to the success of this research.

International Materials Reviews publishes critical reviews of the literature by acknowledged experts on all aspects of materials science and engineering. It is a journal of the Institute of Materials, Minerals and Mining and ASM International and is published on their behalf by Maney Publishing. Maney’s MORE OpenChoice option offers authors the opportunity for rapid open access publication, ensuring the widest possible dissemination of their research.

‘Self-healing polymers and composites’ by T. C. Mauldin and M. R. Kessler, International Materials Reviews, Volume 55, Number 6, November 2010 , pp. 317–346.

For more information on open access publishing with Maney click here.