Ultraviolet absorber ke tlatsetso ea bohlokoa haholo lihlahisoa tsa polasetiki. Ke mofuta oa stabilizer o sebetsang joaloka stabilizer e khanyang. Haholo-holo e hlahisa phello e tsitsitseng ka ho monya le ho fetola karolo e senyang ea mahlaseli a letsatsi. Li-absorber tsa ultraviolet li sebelisoa haholo-holo lihlahisoa tsa polasetiki, tse kang lipoleiti, likhoele, liphaephe le lihlahisoa tse ling tse teteaneng. Maemong a mangata, li-absorber tsa ultraviolet li boetse li kenngoa lifiliming tsa polasetiki ho thibela kapa ho liehisa liphello tse mpe tsa khanya ea ultraviolet linthong kapa linthong tse sirelelitsoeng. phello.
Mahlaseli a Ultraviolet le litlamorao tsa ona tse senyang lipolymers joalo ka polasetiki
Kaofela rea tseba hore maqhubu a motlakase a tsoang letsatsing a pharaletse haholo, ’me mahlaseli a ka fihlang fatše haholo-holo a akarelletsa mahlaseli a ultraviolet, khanya e bonahalang le mahlaseli a infrared. Matla a mahlaseli a fapane ka mokhoa o fapaneng le oavelength, ha leqhubu le le khuts'oane, matla a maholo le ho feta. Har'a tsona, mahlaseli a mahlaseli a kotsi a marang-rang a 290nm-400nm a na le bolelele bo bokhutšoanyane ka ho fetisisa le matla a phahameng ka ho fetisisa, hape ke a senyang ka ho fetisisa ho li-polymers tse kang polasetiki. Matla a tlamahano ea li-polymer tsa manyolo hangata a maemong a 290 ~ 400kJ / mol, kahoo ho bonolo bakeng sa mahlaseli a ultraviolet a senyehileng. Ka hona, mahlaseli a ultraviolet ke eona ntho e ka sehloohong e amang ho etsa lifoto tsa polasetiki. Leha ho le joalo, hoa lokela ho hlokomeloa hore metsoako ea polymer e nang le meaho e fapaneng e na le kutloisiso e fapaneng ho lihlopha tse fapaneng tse telele le tse khutšoane tsa mahlaseli a mahlaseli a kotsi.
Lebaka leo ka lona lisebelisoa tsa polymer joalo ka polasetiki li nang le thepa e ngata e ntle haholo ke ka lebaka la liketane tsa tsona tse telele tse lekaneng tsa macromolecular. Leha ho le joalo, ka lebaka la bolelele bo khutšoanyane le matla a matla a mahlaseli a ultraviolet, tlas'a ts'ebetso ea mahlaseli a ultraviolet (haholo-holo ka ho kenya letsoho ha oksijene), lisebelisoa tsa polymer li monya Ka mor'a mahlaseli a ultraviolet, ho bonolo ho theha boemo ba thabo ea elektronike. Limolek'hule sebakeng sena se thabileng li ka baka letoto la liketso tsa photochemical, ke hore, karabelo ea mahala ea radical chain, 'me ka nako e ts'oanang, "photooxygen aging" kapa "photooxidation reaction" e etsahala ka oxidation. Liketane tsa macromolecular tsa polymer lia khaoloa kapa li tšela-li amahanngoa ho isa bohōleng bo itseng, e leng se amang ka kotloloho ts'ebetso ea thepa ea polymer, kahoo ho hlaha letoto la liketsahalo tsa botsofali. Tse kang ho fifala, brittleness, ho thatafala, ho phunyeha ha holim'a metsi, le ho senyeha ha thepa ea mechine le ea motlakase, e le hore qetellong e lahleheloe ke boleng ba eona ba tšebeliso.
Mohopolo le ts'ebetso ea mochini oa UV
Lisebelisoa tsa polymer li na le meaho e fapaneng ea limolek'hule, 'me ho hanyetsa ha bona leseli la ultraviolet ho fapane ka tlhaho, ho bolelang hore lisebelisoa tse fapaneng tsa polymer li na le "photostability" e fapaneng. Bakeng sa lisebelisoa tsa polymer tse nang le li-unsaturated bond tse kang li-bond tse peli tse kang ABS le SBS, li bonolo ho monya leseli la ultraviolet le ho ba le liphetoho tsa photooxidation, kahoo photostability ea tsona ha e ntle. Empa bakeng sa polima e hloekileng e nang le litlamo tsa lik'hemik'hale tse tletseng feela, ha e monye kapa ha e amohele khanya ea ultraviolet, kahoo e tsitsitse ho khanya ea ultraviolet.
Empa boemo ba sebele ke hore mofuta ona oa polymer e hloekileng e nang le litlamo tse tletseng li-saturated ha e eo, hobane ts'ebetsong ea tlhahiso ea liindasteri ea li-polymers, tse kang polymerization, extrusion granulation, molding ea ente, polokelo, joalo-joalo, ka mokhoa o ke keng oa qojoa ho hlahisa masala a catalyst, litšila tse ling tse kang trace hydroperoxides li na le kutloelo-bohloko, 'me ka mor'a hore li amohele mahlaseli a kotsi a mahlaseli a kotsi a mahlaseli a kotsi.
Li-absorber tsa UV hajoale ke sehlopha se sebelisoang haholo sa li-stabilizers tsa leseli. E ka monya ka matla le ka boikhethelo -lebone la ultraviolet la matla, 'me ea lokolla kapa ea sebelisa matla a mocheng e le matla a mocheso kapa mahlaseli a fokolang a se nang kotsi a fokolang-ka mokhoa oa ho fetola matla, kahoo e thibela chromophore ka polasetiki ho monya matla a ultraviolet.
Sehlopha sa li-Absorbers tsa UV
Lisebelisoa tsa UV li kenyelletsa metsoako e mengata e fapaneng. Ho ea ka sebopeho, haholo-holo e kenyelletsa benzophenones, salicylates, benzotriazoles, acrylonitriles, triazines, joalo-joalo. Tse sebelisoang haholo indastering ea polasetiki ke benzophenones le benzotriazoles.
Li-absorber tsa Benzophenone tsa UV ha joale ke mofuta o sebelisoang haholo oa li-absorber tsa UV. Li monya hoo e ka bang mefuta eohle ea UV. Mochine o ka fotohang ke hydroxyl hydrogen lesale la benzene le carbonyl e haufi le molek'hule. Litlamo tsa hydrogen tsa intramolecular li thehoa pakeng tsa oksijene, ho etsa selikalikoe sa chelation, 'me ha matla a khanya ea ultraviolet a kenngoa, molek'hule e na le ho sisinyeha ha mocheso, bond ea hydrogen e robehile,' me lesale la chelation le bulehe, e le hore leseli le kotsi la ultraviolet le ka fetoloa ho se kotsi ho lokolloa matla a kotsi a mocheso. Ka diphenyl ketone ultraviolet absorber, ho tlameha ho ba le sehlopha sa ortho hydroxyl, ho seng joalo se ke ke sa sebelisoa e le stabilizer e khanyang bakeng sa li-polymers. Mefuta e tloaelehileng ea moemeli oa mofuta ona oa ultraviolet absorber e kenyelletsa UV-531, UV-9 joalo-joalo.
Li-absorber tsa UV tsa Salicylate ke mofuta oa pele oa li-absorber tsa UV. E ka theha maqhama a haedrojene ka har'a molek'hule, bokhoni ba eona ba ho monya leseli la ultraviolet bo tlase haholo, 'me bolelele ba maqhubu a ho monya bo moqotetsane haholo (ka tlase ho 340nm). Leha ho le joalo, ka mor'a ho monya tekanyo e itseng ea matla, tlhophiso ea limolek'hule e etsahala. Sebopeho sa benzophenone se nang le bokhoni bo matla ba ho monya leseli la ultraviolet se thehoa, ka hona se hlahisa phello e matla ea photostabilization.
Mokhoa oa ho tsitsisa leseli oa benzotriazole ultraviolet absorbers o tšoana le oa benzophenones, hape ho na le lesale la hydrogen bond chelating ka molek'hule, e entsoeng ke hydroxyl oxygen le nitrogen sehlopheng sa triazole. Ha khanya ea ultraviolet e monngoa, tlamo ea hydrogen e ea robeha kapa e fetoloa phototautomer, e fetola matla a kotsi a ultraviolet matla a mocheso a se nang kotsi. Mefuta e tloaelehileng e emelang mofuta ona oa ultraviolet absorber e kenyelletsa UV-P, UV-326, UV-327, UV-329 joalo-joalo.
