Monovinyl

Monovinyl is a term used in polymer chemistry to describe a molecule that contains a single vinyl group, typically the vinyl group CH2=CH–. This functional group is highly reactive in addition polymerization, allowing the molecule to form long polymer chains under radical, cationic, or coordination polymerization conditions. A monovinyl monomer can participate in chain growth but generally cannot form crosslinks by itself because it has only one reactive vinyl site.

Examples of common monovinyl monomers include styrene (vinyl benzene), vinyl chloride, vinyl acetate, acrylonitrile, methyl methacrylate, and various acrylates such as butyl acrylate or 2-ethylhexyl acrylate. These monomers are widely used to produce polymers like polystyrene, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, and poly(methyl methacrylate), among others.

In polymer formulations, monovinyl monomers are often copolymerized with other monovinyl monomers or with multifunctional monomers (divinyl, tri- or higher functionality) to tailor properties or to enable crosslinking. Crosslinks can be introduced by using difunctional or polyfunctional comonomers or additives that react during or after polymerization.

Significance of monovinyl monomers lies in their versatility and ubiquity across plastics, coatings, adhesives, and elastomeric materials. The presence of a single vinyl group defines their reactivity and helps determine the structure and properties of the resulting polymer.