Butüülkummil

Butüülkummil is a synthetic rubber that is a copolymer of isobutylene and a small amount of isoprene. Its defining characteristic is its exceptionally low gas permeability, making it highly resistant to the passage of gases and liquids. This property is a result of its tightly packed molecular structure, which has minimal double bonds compared to other synthetic rubbers.

The primary applications of butyl rubber stem from its impermeability and resistance to ozone, weathering, and heat. It is widely used in the manufacturing of inner tubes for tires, as well as in the production of seals, gaskets, and vibration damping components. Its inertness also makes it suitable for applications in the pharmaceutical industry, such as stoppers for vials and plungers for syringes, where maintaining the purity of the contents is crucial.

Butyl rubber exhibits good resistance to many chemicals, including acids, alkalis, and polar organic solvents. However, it is less resistant to non-polar organic solvents, oils, and greases. It can be vulcanized using various methods, typically involving sulfur or peroxides, to enhance its strength and elasticity. The production of butyl rubber involves cationic polymerization of isobutylene and isoprene at low temperatures. Its unique combination of impermeability and resilience has cemented its importance in a diverse range of industrial and consumer products.