Radical photopolymerisation reactions under air upon lamp and diode laser exposure: The input of the organosilane radical chemistry

摘要

One of the well-known drawbacks of free radical polymerisation in UV curing systems is oxygen inhibition. Depending on the lifetimes of excited states, molecular oxygen may quench excited states. Further, both initiating and propagating radicals are scavenged by oxygen, forming relatively stable peroxy radicals that are unable to participate in further polymerisation radicals. Oxygen inhibition can be a particular problem in thin films and low viscosity films where oxygen diffusion into the film is competitive with the curing process, since polymerisation only occurs once oxygen has been consumed. In recent years, the authors have published a number of papers examining the addition of silanes as a means to breakdown peroxy radicals and form new initiating radicals.