Photoinitiators are substances that can absorb radiant energy and undergo chemical changes to produce reactive intermediates with initiator polymerization ability. They are one of the main components required by any UV curing system.
Photoinitiators can be divided into hydrogen abstraction type and cracking type.
The hydrogen abstraction type requires a compound containing active hydrogen (generally called a co-initiator) to form free radicals through the hydrogen abstraction reaction. It is a bimolecular photoinitiator;
The cleavage type is a single-molecule photoinitiator that decomposes into free radicals in the molecule after being irradiated by a laser.
The principles to be followed when choosing a photoinitiator include high light absorption efficiency in the UV range, good stability, and low cost.