Addition Polymerisation
Polymerisation in which unsaturated monomers add to one another with no loss of any atoms.
Formula / equation
n CH₂=CH₂ → –(CH₂–CH₂)ₙ–
Unit
Dimensionless
In depth
The pi bond opens and the monomers link into a chain, so the polymer has the same empirical formula as the monomer and the process is perfectly atom-economical. It proceeds by radical, cationic, anionic or coordination mechanisms depending on the catalyst.
Examples in the real world
Polythene, polypropene, PVC, polystyrene and PTFE — all from alkene monomers.