repolymerizes

Repolymerizes is the third-person singular present tense form of repolymerize, a term used in polymer chemistry to describe the process of forming polymer chains again from monomeric or oligomeric units. In practice, repolymerizes describes situations where fragments that have been broken down or partially depolymerized are linked into polymer chains under conditions that favor bond formation.

The concept is central to chemical recycling and to certain polymerization strategies. In chemical recycling, plastics are depolymerized to monomers or low‑molecular‑weight fragments, which can then repolymerize to reconstitute polymers that resemble the original material. This route relies on reversible bond formation, suitable catalysts, and reaction conditions that shift the system toward polymer growth rather than further degradation. In living or controlled polymerizations, chain ends remain active and can repolymerize when fresh monomer is introduced, enabling precise control over molecular weight and architecture.

Repolymerization is influenced by thermodynamics and kinetics. The thermodynamic favorability of polymer formation, purity of the monomer feed, presence of impurities or chain ends, and the choice of catalyst or initiator all determine whether repolymerization proceeds efficiently. Some polymers depolymerize readily under heat or chemical treatment, while others resist repolymerization due to unfavorable equilibria, strong intermolecular interactions, or irreversible side reactions.

Examples of repolymerization applications include the chemical recycling of polymers such as PET and polystyrene, where depolymerized components can be repolymerized under appropriate conditions to yield new polymer material. Although promising for sustainability goals, practical repolymerization faces challenges related to energy requirements, material purity, and maintaining polymer properties.

See also: depolymerization, chemical recycling, living polymerization, condensation polymerization.