Which term refers to the chemical that initiates the polymerization reaction when exposed to light?

Which term refers to the chemical that initiates the polymerization reaction when exposed to light?

• A. Photoinitiator
• B. Catalyst
• C. Binder
• D. Solvent

Answer: (A)

Photoinitiator is the term for the chemical that starts the polymerization when exposed to light. It absorbs photons and forms highly reactive species, such as free radicals or cations, that kick off the chain-growth process that links monomers into a polymer. This is why light-activated systems can be controlled precisely—the initiation happens only when the photoinitiator is illuminated. A catalyst merely speeds up a reaction and isn’t defined by light activation in this context. A binder is the film-forming component that holds the coating together, not the trigger for polymerization. A solvent dissolves ingredients and often evaporates away; it doesn’t initiate polymerization. In UV- or light-curable applications, photoinitiators are essential for turning the light signal into a polymer network.

Photoinitiator is the term for the chemical that starts the polymerization when exposed to light. It absorbs photons and forms highly reactive species, such as free radicals or cations, that kick off the chain-growth process that links monomers into a polymer. This is why light-activated systems can be controlled precisely—the initiation happens only when the photoinitiator is illuminated. A catalyst merely speeds up a reaction and isn’t defined by light activation in this context. A binder is the film-forming component that holds the coating together, not the trigger for polymerization. A solvent dissolves ingredients and often evaporates away; it doesn’t initiate polymerization. In UV- or light-curable applications, photoinitiators are essential for turning the light signal into a polymer network.