Synthesis And Characterization Of Acylphosphine Oxide Modified Phoyoinitiators

As a 5E technology?efficient,enabling,economical,energy-saving,and environmental-friendly?,photopolymerization has been widely used in various industrial applicationsincluding coatings,paints,inks,adhesives,optoelectronics,stereolithography,and nanotechnology.Photoinitiator is one of most important part of light curing system.Traditional small molecule photoinitiators have many problems,such as wavelength mismatch with UV-LED light sources,migratory and oxygen inhibition effects.The decrease of the light-absorbing ability of the initiator affects the performance of the polymer material.Therefore,The synthesis of low mobility and matching with LED light sourcephotoinitiatorscan rapidly promoted the development oflight-curing technology.In this study,long-wave absorption photoinitiators Ethyl?2,4,6-trimethylbenzoyl?phenylphosphinate?TPO-L?were selected as starting materials.Under the action of sodium iodide,it was hydrolyzed into 2,4,6-trimethylbenzoyl phenylphosphonic acid?TPO-OH?.Then respectively reaction with perfluorinated octyl ethyl alcohol,lauryl alcohol.At the same time,the acrylate structure was connected to TPO-Land TPO.Two kinds of floating photoinitiators and two kinds of photoinitiators with low migratory were prepared.The structures of these photoinitiators were characterized by ¹H NMR,¹³CNMR and high-resolution mass spectrometer?HR-MS?.Study on the migratory and counteracting oxygen inhibition properties of the photoinitiators by XPS,DPC,ATR,contact method and static contact angle.In light-curing systems,a large number of floating photoinitiators are concentrated on the surface of the system.After absorption of light energy,a large amount of active radicals are generated locally to counteract oxygen inhibition,and part of the initiators undergo photopolymerization.Due to the incorporation of polymerizable functional groups into traditional photoinitiators,their migratory in polymeric materials is reduced.The content and conclusions are described as below:1?The floating photoinitiator and the polymerizable photoinitiator have the same photoinitiating activity as the starting material.Initiating monomer photopolymerization,which lead a high double bond conversion and the maximum reaction rate.2?In a short period of time,the photoinitiators TPO-F and TPO-C show a clear gradient distribution in the photocuring system and have good floating performance,which enrich in the surface layer of the system counteract oxygen inhibition effectively3?Compared with traditional photoinitiators,polymerizable photoinitiators can solve the problem of migratory effectively.