No More Flat Tires? Scientists Make Rubber That Can Heal Itself

[Debby ♥Many Nations♥]

Few things will ruin a day faster than a flat tire. But what if you never had to break out that spare again? Scientists have developed a new type of rubber that can heal itself after a tear or break. 

Amit Das and his colleagues at the Leibniz Institute for Polymer Research in Dresden, Germany published their research in ACS Applied Materials and Interfaces. 

The researchers have modified commercial grade tire rubber with a carbon and nitrogen additive that lets rubber reform crucial bonds. When torn, their rubber can recover the durability and elasticity that vulcanization gives.

Youtube:American Chemical Society

Invented by Charles Goodyear, chemical cross-linking of rubbers by sulfur vulcanization is the only method by which modern automobile tires are manufactured. The formation of these cross-linked network structures leads to highly elastic properties, which substantially reduces the viscous properties of these materials.

Here, we describe a simple approach to converting commercially available and widely used bromobutyl rubber (BIIR) into a highly elastic material with extraordinary self-healing properties without using conventional cross-linking or vulcanising agents. Transformation of the bromine functionalities of BIIR into ionic imidazolium bromide groups results in the formation of reversible ionic associates that exhibit physical cross-linking ability.

The reversibility of the ionic association facilitates the healing processes by temperature- or stress-induced rearrangements, thereby enabling a fully cut sample to retain its original properties after application of the self-healing process. Other mechanical properties, such as the elastic modulus, tensile strength, ductility, and hysteresis loss, were found to be superior to those of conventionally sulfur-cured BIIR.

This simple and easy approach to preparing a commercial rubber with self-healing properties offers unique development opportunities in the field of highly engineered materials, such as tires, for which safety, performance, and longer fatigue life are crucial factors.

source:pubs.acs.org