Synthesis And Photochemical Application Of A-D-A Dopyrrole Compounds

With the development of the times and the progress of science and techno logy,photoinitiators have gradually occupied an important position in the field of light curing.The complete components or formulations are photopolymerized under irradiation of different light sources by their addition.Therefore,the desi gn synthesis is matched to the LED light source and has a good introductionef ficiency of photoinitiators with important research significance.This paper synth esizes the six kinds of A-D-A structural and pyrrole compounds.Studies on th eproperties of the spectrum,geometric structure and photoreactivity and applicat ion.First,three nitrophenyl-1,4-dihydropyrrolo[3,2-b]pyrrole compound Py-NO₂-H,Py-NO₂-CH₃ and Py-NO₂-OCH₃ containing three nitro-nitrogen-containing pa rallel-containing compounds were synthesized by the cyclization reaction.They are polymerized dynamic properties with both monomers(TMPTA and PEGD A).UV-visible absorption spectroscopy and steady-state spectrum show that as the light timeincreases,the absorption strength of the ultraviolet maximum abso rption peak isreduced,and there is a new absorption peak of blue-shifted or re d shift,indicating that the initiator has a fluid solution.The photopolymerizatio n performanceof Py-NO₂-H at 365 nm is preferably 80%and 60%,respectively,witha double bond conversion of two monomers.Electronic paramagnetic reson ancetestalso detects a free radical initiation polymerization.Studies have found that theinitiator has better photoinitiators at visible light waves.Under 405 nm and higher,the TMPTA system can be deeply cured,and the curing depth incr eases with time,up to 17 mm,also Research on photoinitiator and monomer c omplete system.Second,it is designed to synthesize the trifluoromethylpyrrole initiator Py-CF₃-H,Py-CF₃-CH3 and Py-CF₃-OCH₃,under 405 nm steady-state photolymeriz ation conditions,the three initiators of ultraviolet The maximum absorption pea k is rapidly declining,and a new peak that appears,indicating that the syntheti c initiator matches the 405 nm LED.The free radical polymerization of the Py-CF₃-H initiator and the TMPTA system has excellent curing effect,and thedou ble bond conversion is up to 72%under 405 nm LED.Py-CF₃-H photoreactive mechanism was studied by nuclear magnetic resonance(NMR),infrared spectro scopy(IR)and electronic paramagnetic resonance spectroscopy.The photopolym erization 3D printing of the initiator is realized by the LCD printer.In addition,several Py BN similar photoinitiators Py BS,Py I and Py F have paved the photoi nitiator after the research group,and it is desirable to further improve photorea ctive performance.This paper uses a step synthesis method to prepare a new and pyrrole init iator,which has ultraviolet light and visible photocolymerization characteristics,and there is a potential application value in the field of photopolymerization.