vinylkloorimonomeerin

Vinylkloorimonomeerin, also known as vinyl chloride monomer (VCM) or chloroethene, is the organochlorine compound with the formula CH2=CHCl. It is a colorless gas or low-boiling liquid at room temperature, highly flammable, and it has a distinct sweet odor. It polymerizes readily, so it is typically stored and transported in closed systems with polymerization inhibitors to prevent unintended polymer formation.

Chemistry and properties: The molecule features a vinyl group attached to a chlorine atom, enabling addition polymerization to form polyvinyl chloride (PVC). VCM is denser than air and can form explosive mixtures with air under certain conditions. It is reactive with strong oxidizers and is a volatile organic compound that requires careful handling to avoid hazards.

Production: The dominant industrial route to vinyl chloride monomer starts with the chlorination of ethylene to produce ethylene dichloride (1,2-dichloroethane), which is then subjected to dehydrochlorination to yield vinyl chloride and hydrogen chloride. A historical alternative route used the hydrochlorination of acetylene. Modern processes emphasize safety, energy efficiency, and emission controls.

Uses: The primary application of vinyl chloride monomer is as the feedstock for polymerization to polyvinyl chloride (PVC), one of the most widely produced plastics. PVC is used in pipes, vinyl siding, cable sheathing, flooring, packaging, and numerous other products.

Safety and regulation: VCM is toxic and a known human carcinogen; inhalation exposure can irritate the respiratory system, and long-term exposure is associated with liver angiosarcoma and other cancers. Regulatory agencies set exposure limits and require strict handling, containment, and monitoring. Storage and transport are conducted under controlled conditions to minimize leaks and accidental polymerization.

Environmental impact: As a volatile organic compound, VCM can contribute to air pollution and ozone formation. Plants employ emission controls, leak detection, and capture systems to mitigate environmental release.