Ama-absorber e-Ultraviolet angakwazi ukumunca ngokuqinile futhi ngokukhetha imisebe ye-ultraviolet ephezulu, futhi asebenzise ukuguqulwa kwamandla ukuze akhiphe amandla amuncwa njengamandla okushisa noma angabi nangozi aphansi-emisebeni yamandla aphansi, ngaleyo ndlela agweme ukulimala esikhumbeni futhi avimbele ukulimala kwe-polymer. Ukumunca amandla e-ultraviolet kubangela ukuthakasela bese kuba nokubola kwesithombe nesithombe samakhemikhali. Ihlukaniswe ngesakhiwo, ikakhulukazi ihlanganisa ama-benzophenones, ama-salicylates, ama-benzotriazoles, ama-substituted compounds, ama-triazines, njll. Okusetshenziswa kakhulu embonini yepulasitiki ama-benzophenones nama-benzotriazoles. I-Benzophenone UV absorbers okwamanje iwuhlobo olusetshenziswa kakhulu lwe-UV absorbers. Bamunca cishe lonke uhla lwe-UV. I-photostability mechanism iyi-hydroxyl hydrogen eseringini ye-benzene kanye neqembu eliseduze le-carbonyl ku-molecule. Amabhondi e-hydrogen e-intramolecular akhiwa phakathi kwama-oxygen, enza indandatho ye-chelation. Lapho amandla okukhanya e-ultraviolet emuncwa, ama-molecule abhekana nokudlidliza okushisayo, izibopho ze-hydrogen ziyabhujiswa, futhi indandatho ye-chelation iyavuleka, ngaleyo ndlela iguqule ukukhanya okuyingozi kwe-ultraviolet kungabi yingozi Amandla okushisa ayingozi akhululwa. Ku-benzophenone ultraviolet absorbers, kufanele kube neqembu le-hydroxyl endaweni ye-ortho, ngaphandle kwalokho ayikwazi ukusetshenziswa njengesiqinisi sokukhanya se-polymer. Izinhlobo ezijwayelekile ezimele lolu hlobo lwe-UV absorbers zifaka i-UV-53UV-9 njalonjalo. Ifomula yesakhiwo samangqamuzana e-UV-531 kanye nezidonsa ze-UV ze-salicylate ezingokomzimba ziwuhlobo lwakuqala lwezibambisi ze-UV ezisetshenziswayo.
1. I-Benzophenone UV absorbers iwuhlobo olusetshenziswa kakhulu lwe-UV absorbers. Lolu hlobo lwe-ultraviolet absorber lunomphumela wokumunca kancane ku-uV-A, uV-B, ne-uV-C. Iqembu le-ketone neqembu le-hydroxyl ku-molecule lingakhiqiza izibopho ze-hydrogen zangaphakathi ukuze zakhe indandatho ye-chelate. Ngemva kokumunca amandla okukhanya e-DUV, ithola ukudlidliza okushisayo kwe-molecule, ibhubhise izibopho ze-hydrogen zangaphakathi, futhi ivule indandatho ye-chelate. Iguqula amandla okukhanya kwe-ultraviolet ibe amandla ashisayo futhi iwakhulule. Ngaphezu kwalokho, iqembu le-carbonyl ku-molecule lizomuncwa amandla okukhanya kwe-ultraviolet amuncwa. I-excitation ikhiqiza i-tautomerism futhi ikhiqize isakhiwo se-enol. Lokhu futhi kudla ingxenye yamandla. Kulolu hlobo lwe-Absorber ye-UV, amandla esibopho se-hydrogen ngaphakathi kwe-molecule ahlobene nomphumela wayo wokuthwebula izithombe. Lapho ibhondi ye-oksijini iqina, amandla amakhulu adingekayo ukuyicekela phansi, futhi lapho amandla e-UV esetshenziswa ekumunceleni, umphumela uba ngcono; ngendlela efanayo. Ngokunjalo. Umphumela wokuzinzisa uhlobene nobude beketango le-alkoxy eringini ye-benzene. Uma kuyinde futhi kunokuhambisana okuhle ne-polymer, umphumela wokuzinzisa uzoba olungile. Kuma-benzophenone{17}asuselwa ku-UV absorbers, kufanele kube neqembu le-hydroxyl endaweni ye-ortho yeqembu le-carbonyl, ngaphandle kwalokho ibhondi ye-hydrogen yangaphakathi ayikwazi ukwakheka futhi ayikwazi ukusetshenziswa njengesibambisi se-UV. Izimunyisi ze-UV ezineqembu le-ortho hydroxyl zingamunca u-290~380~ m wemisebe ye-ultraviolet, cishe kungabikho ukumuncwa kokukhanya okubonakalayo, akukho mbala, nokuhambisana kahle nama-polymer. Uma kunamaqembu amabili e-hydroxyl endaweni ye-ortho yeqembu le-carbonyl, ingakwazi ukumunca ukukhanya kwe-ultraviolet okungama-300 kuya ku-400fzm futhi ibambe ingxenye yokukhanya okubonakalayo. Ngenxa yokumuncwa kokukhanya okubonakalayo, ukukhanya okuhambisanayo akulinganiseli, okwenza izinto ezingezwe ngale mfiva ye-ultraviolet zibonakale ziphuzi. Ngama-polymers aphezulu e-Molecular nawo awahambisani kahle, ngakho-ke ukusetshenziswa kwawo kunomkhawulo. Nakuba i-benzophenone engenawo{27}}amaqembu e-hydroxyl nayo inamandla okumunca imisebe ye-ultraviolet, izobangela ukubola kwayo lapho ivezwe ekukhanyeni, ngakho ayifaneleki ukusetshenziswa njengesibambisi se-ultraviolet.
2. I-Salicylate UV absorber yizona ezasetshenziswa kuqala. I-salicylate nayo inamabhondi e-hydrogen angaphakathi ku-molecule. Amandla alolu hlobo lwe-absorption ye-ultraviolet yokumunca imisebe ye-ultraviolet aphansi kakhulu ekuqaleni, futhi uhla lokumunca luncane kakhulu (ngaphansi kuka-340vm). Nokho, ngemva kokukhanyiswa ngemisebe ye-ultraviolet isikhathi esithile, ukumunca kwayo kancane kancane kuyakhula kuze kube yilapho imunca. Lokhu kungenxa yokukhanya kwayo Ngaphansi kwe-ultraviolet, ukuhlelwa kabusha kwamangqamuzana kwenzeka, kwakha isakhiwo se-benzophenone esinamandla okumunca i-ultraviolet, ngaleyo ndlela kuqinisa umphumela wawo wokumunca i-ultraviolet. Ngakho-ke, abantu bayibiza ngokuthi i-absorber ultraviolet eyiphayona. I-bishydroxybenzophenone kanye nokuphuma kwayo okukhiqizwa ngemva kokuhlelwa kabusha kwamangqamuzana kungakwazi ukumunca ingxenye yokukhanya okubonakalayo futhi kubonakale phuzi, okubangele ukuthi izinto ezengezwe nalesi sinqamuleli se-ultraviolet zibe phuzi.
3. Indlela yokusebenza ye-benzotriazole UV absorbers ifana neye-benzophenones. I-Benzotriazoles inohlu olubanzi lokumuncwa kwemisebe ye-ultraviolet futhi ingamunca ukukhanya ngobude obungamaza obungama-300~400~m. Ayikutholi ukukhanya okungaphezulu kuka-400~m, ngakho-ke umkhiqizo ngeke uguqulwe umbala. Ukwengeza, indlela yokusebenza ye-acrylonitrile eshintshiwe kanye ne-triazine ultraviolet absorbers kucatshangwa ukuthi i-cis-i-trans isomerization, ukuguqula amandla okukhanya noma ukukhipha amandla angenabungozi. I-Acrylonitrile-ama-absorber e-ultraviolet ashintshwayo angakwazi ukumunca ukukhanya kwe-ultraviolet okungu-290 kuya ku-320 Fm, futhi awamumbi ukukhanya okubonakalayo, futhi ngeke abangele into esetshenzisiwe ukuthi ishintshe umbala. -izinqamuli ze-ultraviolet zezinhlobo ezintathu zingamunca ukukhanya kwe-ultraviolet okungu-300~400~m. Ama-absorption e-Ultraviolet angakwazi ukumunca ama-chromophore asizayo (njengokuthi -NH, -OH, -SOH, -cOOH, njll.) kanye namaqembu e-chromophoric (afana ne-C:N, N:N, N:O, C) ngamaza amaza angaphansi kuka-400~m. :O njll.). Zonke zixhunywe kumongo onuka kamnandi. I-Organic nickel ingasetshenziswa futhi njengesinqamuli se-ultraviolet, kodwa ngokuvamile ihlukaniswa njengesicisha (esaziwa nangokuthi isicisha noma i-matting agent, noma isicishi se-laser state, isici samandla), futhi ikhono layo lokumunca imisebe ye-ultraviolet liphakeme kunelo lokucisha. Ukuxhumeka kuphansi, kodwa kungavimbela ukuhlukana okubangelwa ukumuncwa kwemisebe ye-ultraviolet yi-polymer. Ama-organic nickel complexes ama-molecule ajatshuliswa ukusebenzisana nama-polymers phakathi nemisebe yokukhanya kwe-ultraviolet, abuyisela isimo esijabulile esimweni esiphansi futhi aguqule amandla e-ultraviolet abe amandla angaphansi{29}}okungabonakali ngaphandle kokudala umonakalo. , ngaleyo ndlela ivikela i-polymer emonakalweni. Ngakho ibizwa ngokuthi i- quencher ngoba indlela yokusebenza kwayo ihlukile kuleyo yezinqamuleli ze-UV ezivamile. Ama-absorber ama-UV ashintsha ukwakheka kwama-molecule ngokwawo, kuyilapho izicishi zikhipha amandla ngokudluliswa kwamandla phakathi kwama-molecule. Ngaphezu kwalokho, ama-ejenti okuvikela ukukhanya I-Carbon emnyama, i-titanium dioxide, i-zinc oxide, i-zinc barium, njll. nazo ziyizinto ezingamunca noma zibonise imisebe ye-ultraviolet. Kumiswa umgoqo phakathi kwe-polymer nomthombo wokukhanya ukuze umunce noma ubonise imisebe ye-ultraviolet ngaphambi kokuba ifike endaweni ye-polymer. Lapho imuncwa futhi ibonakala, ivimba imisebe ye-ultraviolet ukuthi ingangeni ijule ku-polymer. Esebenza kahle kakhulu i-carbon black. Ama-radical scavengers amahhala nawo awuhlobo lwento engakhiqiza i-photostability. Ziyi-piperidine derivatives ene-steric hindrance effects futhi zibizwa ngokuthi i-hindered amine photostabilizers.
