A major part of industrial polymer chemistry, not only for adhesives, but also for plastics, fibres and paints, consists of linking up molecules of general formula CH₂=CXY (vinylic monomers) to form long chains: ­CH₂ ­CXY­CH₂­CXY­ CH₂­CXY­ etc.

When X and Y are both hydrogen we obtain polyethylene, when X is hydrogen and Y is chlorine the result is polyvinylchloride (PVC). Vinylic monomers of importance in reactive adhesives include:
• ethyl cyanoacrylate X = ­CN, Y = ­CO₂ C₂H₅ (the basis of superglue);
• methyl methacrylate X = ­CH₃, Y = ­CO₂CH₃ (the basis of Perspex or Plexiglass); and
• the related polyethylene glycol dimethacrylate:

This polymerisation can be effected by a variety of reactive initiators.

Free radicals can be formed as required in a number of ways:

• thermally, by the breakdown of, for example, benzoyl peroxide:

• by a redox reaction between, for instance, a hydroperoxide and a reducing species:

ROOH + Fe²⁺ ® RO^· + Fe³⁺ + OH^‾

• photolytically, by the action of ultraviolet light on a photoinitiator such as benzoin ether:

Carbanions are not of particular importance in adhesives, but cyanoacrylates, with their two electron withdrawing groups attached to the vinyl group, will not only react with carbanions, but with virtually any nucleophile, such as traces of amine on the skin:

Cations are not used a great deal with vinyl monomers, but are used with some specialised epoxies (the epoxy group can be seen as an oxidised vinyl group). The cations are generated photochemically from species such as Ph₃S+SbF ₆ ^‾.