A team of researchers at the Harvard School of Engineering and Applied Sciences (SEAS) has developed a new method for manufacturing natural rubber that makes it up to 10 times more resistant to cracks and deformation. All of this is thanks to a surprisingly simple idea: softening the vulcanization process.
Gentler vulcanization process, increased resistance
Since Charles Goodyear's time in 1844, vulcanization — the process of heating rubber with chemical agents — hasn't changed much. This results in short, rigid polymer chains that are strong but vulnerable to cracks.
But Harvard scientists had an idea: slow down the process to preserve the long molecular chains, creating more flexible internal structures, comparable in a sense to spaghetti noodles.
The result? Four times greater resistance in initial tests, and up to 10 times better under prolonged stress conditions.
“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, first co-author of the paper that came out of the research project.
Not yet for tires, but ideal for sensitive parts
This new material isn't yet ready to replace tires. Performance of the new compound is still too low due to significant water evaporation during processing. However, other applications like gloves or sealing gaskets could benefit quickly.
And if the technology can be fine-tuned for heavier-duty use, the auto industry could take advantage of it in 10 to 15 years, particularly in hot regions where traditional rubber materials crack over time.
