Nissan’s innovative marketing campaign promoting its self-healing paint technology captured the imagination of the public (and the advertising industry) when it featured in The Economist and on social media.
As part of the campaign, the company announced a self-healing plastic for a mobile phone case that repairs scuffs or scratches. The marketing campaigns highlight the exciting potential of self-healing polymers for everyday uses.
Self-healing polymers are CSIRO research scientist Dr Russell Varley’s area of expertise. These polymers have the ability to sense and automatically repair tiny cracks or fractures within the polymer matrix or on its surface.
Varley’s team has developed a self-healing polymer coating for industrial pipelines. The coating’s ability to self-repair reduces the need for pipeline maintenance, extending the in-service lifetime and reducing servicing costs.
Varley also leads a team developing a new self-healing polymer system, which incorporates particles of a thermoplastic elastomer into an epoxy resin matrix or laminate and employs a unique pressure delivery mechanism. In this polymer, the self-healing process is dormant until thermally activated by mild heat.
This causes bubbles of volatile material inside the particles to expand greatly, pushing their store of thermoplastic healing agent outwards to spread into testing a polymer composite’s fracture cracks, adhere and solidify, and heal the fracture. The particles can be activated multiple times to repair successive minor damages that occur during the lifetime of the item.
The advantage of this ‘dormant until activated’ self-healing process is that it can be used selectively to repair parts during regular inspections for internal cracks caused by fatigue.
“Rather than disassembling the part or replacing it completely, a swift and effective repair can be made simply by placing a heat blanket across the part,” says Varley.
This makes the self-healing polymer system ideal for repairing internally complex components that develop damage from fatigue during use and are expensive to replace and repair conventionally. The capacity for multiple repairs means that minor damage to items made of the CSIRO epoxy resin can be mended a number of times before the item must be replaced.
“”It’s a particularly appropriate system for improving efficiency and reducing maintenance costs in an industrial environment,” says Varley.
CSIRO are also working on tailored thermoplastic polymer systems with the ability to self-heal after high impact damage. “The polymer will even repair itself from impact by a bullet,”Varley says. “It has a lot of potential in protecting infrastructure, like storage tanks, from high impact damage.
CSIRO Business Development Manager
Dr Dilip Manuel Email