SUNNYJOINT Engineering self-healing properties of dry materials such as rubber are difficult to achieve

- Nov 19, 2018-

On the highway, accidents caused by tire blowers are not uncommon. How to reduce the number of tire blows to avoid major accidents has always been a concern. It was learned from Sichuan University that Wu Jinrong, a visiting professor at the school, and Cai Liheng, a postdoctoral researcher at Harvard University, have developed a new self-healing self-healing rubber that is comparable to natural rubber, or is approved for use in automotive tires in the future. With this rubber, the tire can be self-repaired while the tire is in motion and is as strong as natural rubber, greatly improving the overall safety of the motor vehicle and helping to reduce traffic accidents. It is reported that the Harvard Technology Development Office has submitted a patent application for it and is actively seeking opportunities for commercialization.

According to Wu Jinrong, researchers at Harvard University's John Paulson School of Engineering and Applied Sciences (hereinafter referred to as SEAS) have developed a self-healing hydrogel that promotes the healing of reversible bonds by incorporating water.

 The self-healing properties of dry materials such as rubber are difficult to achieve because they are made of polymers that are permanently covalently bonded. Although the covalent bonds are very powerful, once they are broken, they will never reconnect. To this end, Wu Jinrong and two colleagues, together with Harvard University postdoctoral researcher Cai Liheng, decided to develop a hybrid rubber with covalent bonds and reversible bonds. Because the two bonds are as miscible as oil and water, the researchers developed a molecular rope to bind them together, allowing them to mix evenly on the molecular scale, creating a transparent, tough, self-sufficient The more the rubber. “We used cross-linked, cross-linked, branched polymers to successfully bind hydrogen bonds and covalent bonds at the molecular scale. This technology has broad application potential, for example, in the manufacture of self-healing tires. There is no need to replace it immediately after the damage, which helps to reduce the risk of accidents."

It is understood that when the new "self-healing" rubber is subjected to tension, a mesh pattern appears, which is crack-like but does not completely crack, maintaining some fibrous joints. The mesh pattern disperses the tension and prevents the material from being severely broken that cannot be repaired. After the pulling force disappears, the rubber will return to its original shape and retain a tensile strength of approximately 30%.