Isobutylene, also known as 2-Methylpropene or C4H8, with the CAS number 115-11-7, is a hydrocarbon of significant industrial interest. As a colorless, flammable gas, its chemical properties dictate its handling, storage, and extensive applications across various sectors. For professionals in chemical procurement and R&D, a thorough understanding of Isobutylene's characteristics is fundamental.

The molecular formula for Isobutylene is C4H8, and it is one of the isomers of butylene. Its structure features a double bond and a tertiary carbon atom, making it highly reactive in addition and polymerization reactions. Key physical properties include a low boiling point of -6.9 °C, meaning it is typically handled as a liquefied gas under pressure. Its density as a liquid is approximately 0.5879 g/cm³. While it has low solubility in water, it readily dissolves in organic solvents. The autoignition temperature is around 465 °C, and its explosive limits in air range from 1.8% to 8.8%.

The highly flammable nature of Isobutylene is its most significant hazard. It readily forms explosive mixtures with air, and its vapors are heavier than air, meaning they can travel along the ground and flash back to an ignition source. Therefore, strict adherence to safety protocols, including proper grounding of equipment, ventilation, and avoidance of ignition sources, is critical during handling and storage. Containers holding pressurized Isobutylene can rupture violently if exposed to heat or fire.

Health-wise, Isobutylene can cause mild irritation to mucous membranes and has an anesthetic effect at high concentrations, potentially leading to asphyxiation by displacing oxygen. Skin contact with the liquefied gas can cause frostbite. Industrial facilities must implement appropriate personal protective equipment (PPE) and ensure adequate ventilation to minimize exposure risks. Occupational exposure limits are established to ensure worker safety.

From a chemical stability perspective, Isobutylene is generally stable under recommended storage conditions. However, it can polymerize, especially in the presence of catalysts like aluminum chloride or boron trifluoride, or upon prolonged exposure to heat. Understanding these reactions is vital for chemical manufacturers and users to prevent unintended polymerization, which can generate heat and pressure.

For industries relying on Isobutylene, such as polymer manufacturers or fuel additive producers, sourcing from reputable suppliers who provide detailed safety data sheets (SDS) and technical information is crucial. These suppliers often emphasize quality control and safe handling practices. When purchasing Isobutylene, ensuring compliance with all safety regulations and guidelines is as important as the purity of the chemical itself.