Resisting Surface Oxygen Inhibition In UV-Curing Of Acrylic Resin

Surface oxygen inhibition in uv-curing is a puzzle that disturbs people all the long. Resisting oxygen inhibition in uv-curing of acrylic resin was investigated in details.On the base of the process of uv-curing, we analyse the surface oxygen inhibition mechanism and the work on resisting oxygen inhibition before was also evaluated. Then, considering many respect such as light source,diluent and photoinitiator, mainly improving photoinitiating system, we found the solutions to oxygen inhibition of acrylic resin in uv-curing. first, suitable tertiary amines was added to BDK photoinitiator, and the surface oxygen inhibition phenomenon was eliminated. Second, we combined cheap BP and high photosensitive thioxanthone with tertiary amines of good property as hydrogen abstracting photoinitiators, and oxygen inhibition was resisted. Third, Diaryliodonium terafluoroborate was prepared with simple method and identified by IR,UV and 1H-NMR spectroscopy together with melting point. With low absorptivity above 300nm, this iodonium sah was combined with thioxanthone and benzil dimethyl ketal as direct and indirect electron transfer photosensition systems, oxygen inhibition was resisted. Fourth, a three component initiating system, iodonium/ketone/tertiary amine, was attempted and the influence to surface oxygen inhibition was discussed.The work in this paper will take an active part in solving oxygen inhibition and increasing surface curing rate in radical uv-curing.