Ultraviolet absorbers tuaj yeem nqus tau ultraviolet lub teeb vim yog cov qauv ntawm conjugated π-electron system nyob rau hauv cov molecule ntawm hom compound thiab cov qauv uas tuaj yeem txav hydrogen atoms. Kuj tseem muaj cov xwm txheej uas tsuas yog thawj ntu. Ultraviolet absorbers muaj tsawg kawg yog ib qho ortho-hydroxy phenyl hloov pauv hauv cov qauv molecule. Hauv hom kev sib xyaw no, lub nplhaib chelate yog tsim los ntawm pawg ortho-hydroxy thiab nitrogen atom lossis oxygen atom. Tom qab nqus ultraviolet lub teeb, hydrogen daim ntawv cog lus tawg thiab molecular isomerism tshwm sim. , Cov qauv intramolecular undergoes thermal vibration, hydrogen daim ntawv cog lus tau tawg, lub nplhaib chelating yog qhib, thiab cov qauv intramolecular hloov, yog li cov teeb meem ultraviolet hloov mus rau qhov tsis muaj teeb meem thaum tshav kub kub tawm, yog li tiv thaiv cov khoom. Rau cov nquag siv benzophenone thiab Rau benzotriazole ultraviolet absorbers, cov txheej txheem saum toj no tuaj yeem qhia los ntawm cov mis hauv qab no: benzophenone, benzotriazole
Hauv cov txheej txheem no, lub nplhaib chelating tsim nyob rau hauv cov molecule yog tus yuam sij rau nws txoj haujlwm ultraviolet. Lub zog rhiab heev ntawm kev qhib lub nplhaib no yog raws nraim lub zog ultraviolet ntawm 290-400 nm wavelength.
Tsis tas li ntawd, raws li ib qho ultraviolet absorber, nws yuav tsum tsis txhob muaj cov tshuaj tiv thaiv photochemical nyob rau hauv qhov kev txiav txim ntawm ultraviolet lub teeb los yog pom lub teeb; nws muaj kev ruaj ntseg zoo rau cov tshuaj thiab dej, thiab muaj thermal stability zoo; tsawg volatility; compatibility nrog cov ntaub ntawv polymer Nws muaj cov khoom zoo thiab tsis muab rho tawm los ntawm cov kuab tshuaj. Tsuas yog cov tebchaw uas ua tau raws li cov xwm txheej saum toj no tuaj yeem siv ua ultraviolet absorbers.
Raws li cov qauv tshuaj, UV absorbers tuaj yeem muab faib ua benzotriazoles, benzophenones, triazines, salicylates thiab cyanoacrylates, thiab lwm yam.
