Rubber That Doesn’t Grow Cracks When Stretched Many Times

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have increased the fatigue threshold of particle-reinforced rubber, developing a new, multiscale approach that allows the material to bear high loads and resist crack growth over repeated use. This approach could not only increase the longevity of rubber products such as tires but also reduce the amount of pollution from rubber particles shed during use.

The research is published in Nature.

Naturally occurring rubber latex is soft and stretchy. For a range of applications, including tires, hoses, and dampeners, rubbers are reinforced by rigid particles, such as carbon black and silica. Since their introduction, these particles greatly improve the stiffness of rubbers but not their resistance to crack growth when the material is cyclically stretched, a measurement known as the fatigue threshold.

In fact, the fatigue threshold of particle-reinforced rubbers hasn’t improved much since it was first measured in the 1950s. This means that even with the improvements to tires that increase wear resistance and reduce fuel consumption, small cracks can shed large amounts of rubber particles into the environment, which cause air pollution for humans and accumulate into streams and rivers. …

Source: Harvard University