Topic overview

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A radical initiator generates a carbon-centered radical, which adds to an alkene’s π bond and creates a new radical at the growing chain end. Repeated additions extend the chain; coupling or disproportionation can terminate growth. Chain-transfer reagents shift the radical center and can lower molar mass, while inhibitors and retarders quench radicals. The topic links this mechanism to common monomer–polymer pairs and to structural features such as branching and tacticity. It also surveys polymerization media and controlled radical methods, introducing how process choices and polymer structure relate to properties including glass-transition temperature and crystallinity.