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The Drive
12-07-2025
- Automotive
- The Drive
Harvard Found a Way to Make Rubber 10x Tougher and It Could Be Big for Cars
The latest car news, reviews, and features. Natural rubber is a wonder material. Few discoveries or innovations come close to its impact on manufacturing, and the car industry is just one of many that depend on it for critical components, such as gaskets, seals, and tires. There's just one problem: It cracks, and once that happens, it's not good for much. That's why researchers at the Harvard School of Engineering and Applied Sciences started tooling around with natural rubber here recently to see if they could make it more durable. And what do you know, they were able to make it 10 times tougher than before with a tweak to the vulcanization process. See, the science involved in vulcanized rubber production hasn't changed much since Charles Goodyear patented it in 1844. You start with natural rubber latex that comes from Hevea trees, and once it's harvested, it's coagulated, dried, mixed with additives, shaped, and heated. The high-intensity process forms short polymer chains within the material, as the Harvard SEAS writes, resulting in chemical bonds. The Harvard scientists had an idea: 'What if we're gentler with it?' Sounds crazy, I know, but that one tweak brought about a result that surprised even their bright minds. It was instantly four times better at resisting slow crack growth, even after repeated stretching. 'We imagined that the properties would be enhanced maybe twice or three times, but actually they were enhanced by one order of magnitude,' said Zheqi Chen, a former SEAS postdoctoral researcher and first co-author of the paper. Harvard School of Engineering and Applied Science The change in process, which was based on latex processing methods, preserved the long polymer chains rather than forming shorter ones. Long 'tanglemers' inside the material resemble spaghetti noodles rather than a tightly-bound grid. Stress is then able to be spread out across those tanglemers, greatly improving its resistance to cracking and snapping. Not only is it more resistant to cracks, but it becomes tougher under the conditions that would normally cause natural rubber to fail. It wouldn't be accurate to call the material 'self-healing,' but as the new rubber stretches and small cracks form, those spaghetti tanglemers allow more crystallization. That means the overall strength increases under those circumstances. This video demonstrates it well: This process isn't especially well-suited to automotive applications like tires, at least in its current form. Water evaporation is high, yielding a smaller volume of material than companies would want to wrap around a car's wheels. The Harvard SEAS writes that, for now, it's better suited for gloves and other thin applications. You can fill in the blank there, but if scientists can find a way to upscale the process so that it works for automotive seals, then it could be good news for people in sunny climates some 10 to 15 years later. All the people in Phoenix are hoping that the time comes sooner rather than later. Got a tip or question for the author? Contact them directly: caleb@
Yahoo
24-05-2025
- Science
- Yahoo
US scientists make rubber 10 times tougher, 4x more crack-resistant under repeated stress
Materials scientists in the U.S. have just given natural rubber a major upgrade by developing a method to make it stronger and significantly more resistant to cracking, without compromising its signature stretchiness, even after repeated cycles of use. Led by Zhigang Suo, an Allen E. and Marilyn M. Puckett professor of mechanics at materials at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), the study explored crack growth, one of rubber's most persistent weaknesses. According to Suo and his team, while natural rubber has been used for millennia, initially by the indigenous cultures of Mesoamerica, its ability to resist cracking, particularly under repeated stress, has remained largely unimproved. "Improving crack resistance will extend the material's service lifetime and therefore improve its sustainability," Guodong Nian, PhD, a former SEAS postdoctoral researcher and first author of the study. Native to the Amazon basin and sourced from the milky latex of the Hevea tree (Hevea brasiliensis), natural rubber is a durable polymer used in everything from gloves and tires to medical devices, shoes, and conveyor belts. But the research team has now found a way to modify its traditional high-intensity vulcanization process, which usually creates short polymer chains within the material that are densely crosslinked, or chemically bonded. This, according to the team, resulted in a novel type of rubber, which they called tanglemer. Filled with long, entangled polymer strands resembling a bowl of spaghetti, the new rubber reportedly boosts durability by absorbing and distributing stress more efficiently. "We used a low-intensity processing method, based on latex processing methods, that preserved the long polymer chains," Nian explained. According to the scientists the new material is four times more resistant to slow crack growth under repeated stretching, and 10 times stronger overall. This, according to the scientists, is because when a crack forms in it, the long spaghetti strands spread out the stress by sliding past each other, allowing more rubber to crystallize as it stretches, ultimately making the material more resilient. "We imagined that the properties would be enhanced maybe twice or three times, but actually they were enhanced by one order of magnitude," Chen concluded in a press release, adding that the key to the discovery lies in replacing the dominance of chemical crosslinks. Yet, while the research highlights the benefits of preserving long polymer chains, challenges remain as the process requires significant water evaporation, limiting material yield and making it less suitable for larger products such as tires. This currently makes it less suitable for bulky applications like tires, but better suited for thin rubber products such as gloves, condoms, or other items that require flexibility without large material volume. According to the researchers, the new process also opens up possibilities for applications like flexible electronics and components for soft robotics. The study was supported by the National Science Foundation's Materials Research Science and Engineering Centers (DMR-2011754) and the Air Force Office of Scientific Research. It has been published in the journal Nature Sustainability.
