Rubber is everywhere in modern vehicles, from tires to timing belts. Eventually, all these items wear out, usually by cracking after countless cycles of stretching and snapping back into shape. Material researchers at Harvard have recently figured out a different way to make rubber that could last much longer. This new rubber would be four times more resistant to cracking while stretching, resulting in a compound ten times stronger than current materials.
Harvard specifically called out tires as one potential future use for this stronger rubber. Run-flat tires exist, but stronger regular tires that are more resistant to punctures or sidewall damage would be even better. Alternately, less of the strong rubber material would be needed for eco-friendly tires, making them lighter and more sustainable, and contributing to improved fuel economy.
Conveyor belts are another application Harvard mentioned, but my mind immediately went under the hood instead. Serpentine belts could be one application, useful on hard-to-reach engines, but I was thinking more about timing belts. If a timing belt snaps in an interference engine, pistons hit valves, and the entire engine must be rebuilt or replaced. Replacing a timing belt is also a big job and must be done precisely to avoid this kind of damage. Many engines use stronger, more durable timing chains instead of belts, but they are louder and more expensive. If a timing belt could be made ten times stronger, it would be the best of both worlds.
A tangled mess is a good thing
How has Harvard managed to make such a revolutionary advance? Let’s dig into the weeds a bit. If you really want to nerd out, you can read Harvard’s announcement or the original article by the researchers.
This stronger rubber results from a production process closer to that of latex than traditional rubber. As the researchers explain it, standard vulcanization creates short polymer chains within the rubber, which are dense and bound closely to one another. Their alternative is a more gentle process that preserves the longer polymer chains of the material’s natural state. These chains not only connect to each other, but they also interweave, creating a stronger material. Rather than polymer, Harvard calls this substance “tanglemer.”
Imagine a plate of tangled spaghetti compared to a plate of elbows or rotini. If you move a fork through the elbows, the pasta moves easily out of the fork’s way. Move a fork through a plate of spaghetti, and the pasta resists, causing a mess as you shove all your food off the plate instead. This is a simplified but similar version of what’s happening inside these rubber compounds.
The current production process for this stronger rubber uses a lot of water, and is only suitable for thinner rubber at this time. That’s still good news for those of us who hate rubber gloves that tear way too easily. Further research and refinement of this process will hopefully give us stronger, thicker rubber, too.
