1. Lub teeb stabilizer yog dab tsi
Hnub ci yog ib qho hluav taws xob hluav taws xob. Thaum nws hla dhau qhov chaw thiab txheej ozone, yuav luag tag nrho cov rays hauv qab 290nm thiab siab dua 3000nm raug lim tawm. Cov nthwv dej electromagnetic uas tau ncav cuag hauv av yog 290nm ~ 3000nm, ntawm qhov wavelength range yog 400 ~ 800nm (li 40 feem pua) yog pom lub teeb, lub wavelength ntawm txog 800-3000nm (kwv yees 55%) yog infrared, thiab lub wavelength ntawm txog 290-400nm (tsuas yog 5 feem pua) yog ultraviolet.
Ultraviolet rays nyob rau hauv tshav ntuj yog lub ntsiab yog vim li cas rau cov laus cov nyhuv ntawm cov ntaub ntawv polymer. Txawm hais tias lub teeb ultraviolet tsuas yog kwv yees li 5 feem pua ntawm hnub ci, nws muaj zog heev. Tom qab cov khoom polymer absorbs ultraviolet rays, nws yog txaus los ua rau lub polymer rau nws tus kheej-oxidize thiab degrade, rhuav tshem cov tshuaj bonds ntawm lub polymer, tawg thiab hla-txuas nws, thiab ua rau cov tsos thiab lub cev thiab txhua yam khoom ntawm cov khoom polymer. kom deteriorate, thiab lub zog yog txo. , ua neej luv. Cov txheej txheem no hu ua photoredox lossis photoaging. Ultraviolet rays tseem tuaj yeem dhau los ntawm txheej txheej ntawm tus neeg ntawm daim tawv nqaij, rhuav tshem cov hlwb ntawm daim tawv nqaij, ua rau daim tawv nqaij maj mam harden thiab poob nws elasticity, tshwm wrinkled thiab ceev aging.
Lub teeb stabilizer yog ib qho ntxiv rau cov khoom siv polymer (xws li yas, roj hmab, txheej, hluavtaws fibers), uas tuaj yeem tiv thaiv lossis nqus tau lub zog ultraviolet, quench singlet oxygen, thiab decompose hydroperoxides rau hauv cov khoom tsis muaj zog. , nyob rau hauv irradiation ntawm lub teeb, lub polymer tuaj yeem tshem tawm los yog qeeb ntawm cov tshuaj tiv thaiv photochemical, tiv thaiv lossis ncua cov txheej txheem ntawm kev yees duab, thiaj li ua tiav lub hom phiaj ntawm kev ua haujlwm ntev ntawm cov khoom siv polymer.
2. Hom lub teeb stabilizers
l Lub teeb tiv thaiv tus neeg sawv cev: Qhov no yog ib yam khoom uas tuaj yeem tiv thaiv los yog cuam tshuam cov kab hluav taws xob ultraviolet, kom lub teeb tsis tuaj yeem nkag mus rau sab hauv ntawm lub polymer, yog li tiv thaiv cov polymer. Cov tshuaj tiv thaiv lub teeb muaj xws li cov xim tsis muaj xim xws li carbon dub thiab titanium oxide, thiab cov xim organic xws li phthalocyanine xiav thiab phthalocyanine ntsuab, cov pa roj carbon dub muaj qhov zoo tshaj plaws tiv thaiv cov nyhuv.
l Ultraviolet absorber: Nws muaj nuj nqi tuaj yeem nqus tau cov kab hluav taws xob ultraviolet nrog lub wavelength ntawm 290-410nm, tab sis tsis tshua pom lub teeb pom kev, thiab nws muaj thermal stability thiab lub teeb ruaj khov. Raws li nws cov qauv tshuaj, nws tuaj yeem muab faib ua: o-hydroxybenzophenones, benzotriazoles, salicylates, triazines thiab hloov acrylonitriles. Siv los ua tus pab lub teeb stabilizer thiab hindered lub teeb stabilizer, tshwj xeeb tshaj yog nyob rau hauv polyolefins los yog coatings.
l Quencher: Nws tuaj yeem lees txais lub zog nqus los ntawm chromophore hauv cov yas thiab tawm lub zog hauv daim ntawv ntawm tshav kub, fluorescence lossis phosphorescence, yog li tiv thaiv cov polymer los ntawm UV puas. Nws muaj kev ruaj ntseg zoo ntawm cov polymers thiab feem ntau yog siv hauv cov yeeb yaj kiab thiab fibers. Feem ntau ib co divalent organic nickel chelates. Organonickel lub teeb stabilizers muaj kev ua tau zoo, tab sis tej zaum yuav raug hloov los ntawm lwm yam tsis muaj tshuaj lom lossis tsis muaj tshuaj lom quenchers vim muaj cov tshuaj lom ntawm cov hlau hnyav.
l Dawb radical scavenger: Hom lub teeb stabilizer no tuaj yeem ntes cov dawb radicals tsim nyob rau hauv cov polymer, yog li inhibiting cov txheej txheem yees duab-oxidation thiab ua tiav lub hom phiaj ntawm lub teeb stabilization. Feem ntau yog hindered amine teeb stabilizers (HALS). Nws yog qhov kev cog lus tshiab tshaj plaws ntawm kev ua haujlwm siab lub teeb stabilizer, thiab qhov nruab nrab txhua xyoo xav tau kev loj hlob hauv ntiaj teb yog 20 feem pua rau 30 feem pua.
l Hydroperoxide decomposer: Nws yog ib qho ntawm hindered amine teeb stabilizers. Polymers tuaj yeem tsim cov hydroperoxides thaum khaws cia thiab ua haujlwm, ua rau cov duab-oxidative degradation ntawm polymers, thiab hydroperoxide decomposers tuaj yeem decompose peroxides, tsim kom ruaj khov nitrogen-oxygen radicals, thiab ntxiv ntes dawb radicals, yog li inhibiting polymer degradation.
3. Qhov tsis zoo ntawm lub teeb stabilizers
l Tus neeg saib xyuas lub teeb muaj kev tiv thaiv zoo thiab tus nqi qis, tab sis muaj lub teeb-shielding thiab colouring zog, thiab tsuas yog tsim rau cov ntaub ntawv opaque;
l UV absorbers muaj ntau yam siv tau, tab sis vim lawv cov txiaj ntsig tiv thaiv, lawv tsis tuaj yeem tiv thaiv qhov chaw ntawm cov khoom thiab cov khoom nyias. Nyob rau tib lub sij hawm, vim hais tias lawv yog cov ntshiab organic tebchaw, kuj muaj volatile, frosting, tsiv teb tsaws, thiab hnyav extraction. Qhov tsis zoo, uas tsis tsuas yog cuam tshuam rau kev ua haujlwm tsis tu ncua, tab sis kuj ua rau muaj kuab paug ntawm ib puag ncig;
l Zoo siab lub xeev quencher thiab hydroperoxide decomposer muaj siab photostability, tsis tshua muaj volatility, me ntsis blooming thiab tsiv teb tsaws, thiab resistant rau extraction, uas muaj peev xwm tiv thaiv zoo ntawm cov khoom thiab nyias cov khoom. Txawm li cas los xij, cov xim tsaus, qhov toxicity thiab ib puag ncig muaj kuab paug yog loj, thiab nws yuav decompose thiab hloov xim ntawm qhov kub thiab txias, uas muaj cov nyhuv counteracting nrog sulfur-muaj additives;
l Cov dawb radical scavenger yog lub teeb nyob rau hauv cov xim, muaj cov nyhuv zoo ntawm lub teeb stabilization, thiab tuaj yeem tiv thaiv cov khoom thiab cov khoom nyias. Txawm li cas los xij, vim nws cov alkalinity, nws muaj cov nyhuv antagonistic nrog acidic substrates thiab additives. Lub acidic ib puag ncig yuav cuam tshuam rau nws kev ua haujlwm. Nyob rau tib lub sijhawm, zoo li UV absorber, vim tias nws yog ib qho ntshiab organic compound, nws kuj muaj qhov tsis zoo xws li volatile, blooming, tsiv teb tsaws, thiab extraction.
4. Piv txwv ntawm cov mechanism ntawm kev txiav txim ntawm lub teeb stabilizers
1. UVA
2. HALS
