Getting a flat tire might never be an entirely hassle-free experience, but before too long it may no longer be necessary to patch or replace punctured tires. Instead, thanks to research currently being conducted in Europe, damaged tires could just be left a few hours to heal on their own.
Currently, tires are manufactured using the curing process of vulcanization – this involves adding sulfur or other compounds to the rubber, boosting the finished product's durability by forming cross-links between the polymer chains that make up the material. Unfortunately, though, once those links are broken, they can't be repaired.
A team of scientists from the Leibniz Institute for Polymer Research (Germany), the Tampere University of Technology (Finland) and the Dresden University of Technology (Germany) are attempting to get around that limitation, by getting rid of the vulcanization process altogether.
They've discovered that adding a carbon/nitrogen compound has much the same effect, but additionally allows broken polymer links to reform over time.
In lab tests, samples of rubber made using the process were able to heal cuts in themselves at room temperature. Heating the rubber to 212º F (100 ºC) for the first 10 minutes accelerated the process. After a period of eight days, the healed pieces of rubber were able to withstand pressures of up to 754 psi (52 bar) – far higher than any tire has to handle.
According to the researchers, the addition of reinforcing agents such as silica or carbon black could boost the self-healing rubber's strength even farther.
A paper on the research was recently published in the journal ACS Applied Materials & Interfaces.