Synthesis And Photo Polymerization Properties Of Benzophenone Photoinitiator

In recent years,with establishment of the idea of green and sustainable development,UV curing technology has been widely used in many industries and the application prospect is more broad because of its energy saving,high efficiency and non pollution.In the process of photopolymerization,the photoinitiator plays an indispensable role.With the further application of photopolymerization technology,the requirement of photoinitiator with hight performance is also increasing and diversifying.Therefore,the continuously study of photoinitiator that with more Excellent performance and could meet the new application demands has become a very important task.Benzophenone(BP)was one of the most widely used photoinitiator in the field of UV curing currently because of it's easily synthesized and cost-effective.However,it still possesses some shortcomings,such as:easy migration after curing,the efficiency of photoinitiation can still be improved,limit its applications.In this paper,three benzophenone derivatives photoinitiators were synthesized by introducing different functional groups,and their photopolymerization properties were studied.A fluorinated curable benzophenone photoinitiator(FBPAc)was synthesized with 4-fluoro-4'-hydroxy benzophenone and acrylyl chloride via acylation reaction;A polymerizable photoinitiator containing vinyl double bond was synthesized with 4-Hydroxybenzophenone and allyl bromide;A photoinitiator which containing a two benzophenone reaction groups was synthesized from 4-methyl benzophenone and 4-hydroxy benzophenone(HBP)by Bromination and Williams reaction.The product structure and UV absorption properties of the three photoinitiators were studied by IR,NMR and UV.Compared with the traditional small molecule initiators of benzophenone,the properties of red light transfer and absorbance were greatly enhanced.The photopolymerization properties of thes photoinitiators under different concentration,different light intensity and different monomer conditions were studied.It was proved that these three photoinitiators could effectively initiate the photopolymerization reaction,and there is a greater reaction rate and higher final conversion rate compared with commercial benzophenone photoinitiation system under the same conditions.The migration of FBPAc in the solidification material was studied through solvent extraction method,and the results showed that the photopolymerization rate and final conversion rate of FBPAc all is higher than benzophenone under the same conditions,and migration rate of FBPAc is far below than benzophenone migration in poly(Hexamethylene diacrylate).In addition,the thermal stability of three kinds of initiators was studied by thermogravimetric analyzer.The results showed that the thermal stability of the three kinds of initiators was significantly improved.