Dawb, kaj, yooj yim, thiab dawb huv, ua cim qhia txog kev dawb huv.
Muaj coob tus neeg nyiam cov khoom dawb, thiab cov khoom siv feem ntau yog ua los ntawm cov khoom dawb. Feem ntau, cov neeg uas yuav cov khoom dawb lossis hnav khaub ncaws dawb yuav ceev faj kom tsis txhob cia cov khoom dawb muaj cov av qias. Tab sis muaj ib zaj nkauj uas hais tias, "Hauv lub ntiaj teb no, tsis txhob cia mus ib txhis." Txawm koj siv zog npaum li cas los tswj cov khoom no kom tsis txhob qias neeg, lawv yuav maj mam hloov daj ntawm lawv tus kheej. Rau ib lub lim tiam, ib xyoos, lossis peb xyoos, koj hnav lub hnab mloog pob ntseg mus ua haujlwm txhua hnub, thiab lub tsho dawb uas koj tsis tau hnav hauv lub txee khaub ncaws maj mam hloov daj ntawm koj tus kheej.
Qhov tseeb, qhov daj ntawm cov xov khaub ncaws, cov khau hauv qab, thiab cov thawv yas mloog pob ntseg yog qhov qhia txog kev laus ntawm polymer, hu ua daj. Daj yog hais txog qhov tshwm sim ntawm kev puas tsuaj, kev hloov pauv, lossis kev sib txuas ntawm cov molecules ntawm cov khoom polymer thaum siv, tshwm sim los ntawm cua sov, lub teeb ci, oxidation, thiab lwm yam, ua rau muaj qee pawg xim ua haujlwm.
Cov pawg xim no feem ntau yog cov pa roj carbon ob chav sib txuas (C = C), cov pawg carbonyl (C = O), cov pawg imine (C = N), thiab lwm yam. Thaum tus lej ntawm cov pa roj carbon ob chav sib txuas mus txog 7-8, lawv feem ntau tshwm daj. Feem ntau, thaum koj pom tias cov khoom polymer pib tig daj, tus nqi ntawm kev daj feem ntau nce ntxiv. Qhov no yog vim tias kev puas tsuaj ntawm cov polymers yog ib qho kev sib txuas saw, thiab thaum cov txheej txheem kev puas tsuaj pib, kev tawg ntawm cov saw molecular zoo li domino, nrog txhua chav tsev poob tawm ib qho los ntawm ib qho.
Muaj ntau txoj hauv kev los ua kom cov khoom dawb. Kev ntxiv titanium dioxide thiab fluorescent whitening agents tuaj yeem ua kom cov khoom dawb zoo dua, tab sis nws tsis tuaj yeem tiv thaiv cov khoom kom tsis txhob daj. Yuav kom qeeb qeeb qhov daj ntawm cov polymers, cov light stabilizers, light absorbers, quenching agents, thiab lwm yam tuaj yeem ntxiv. Cov hom additives no tuaj yeem nqus lub zog uas lub teeb ultraviolet nqa hauv lub hnub ci, coj cov polymer rov qab mus rau qhov ruaj khov. Thiab cov anti-thermal oxidants tuaj yeem ntes cov free radicals tsim los ntawm oxidation, lossis thaiv qhov kev puas tsuaj ntawm cov saw polymer kom xaus cov saw hlau ntawm cov polymer degradation. Cov khoom siv muaj lub neej ntev, thiab cov additives kuj muaj lub neej ntev. Txawm hais tias cov additives tuaj yeem ua kom qeeb qeeb ntawm cov polymer yellowing, lawv tus kheej yuav maj mam ua tsis tiav thaum siv.
Ntxiv rau kev ntxiv cov khoom ntxiv, nws tseem ua tau kom tiv thaiv cov polymer daj los ntawm lwm yam. Piv txwv li, txhawm rau txo kev siv cov ntaub ntawv hauv qhov kub thiab txias thiab qhov chaw ci ntsa iab sab nraum zoov, nws yog qhov tsim nyog los siv cov txheej txheem nqus lub teeb rau cov ntaub ntawv thaum siv lawv sab nraum zoov. Kev daj tsis tsuas yog cuam tshuam rau qhov tsos, tab sis kuj ua lub cim ntawm kev ua haujlwm tsis zoo lossis ua tsis tiav ntawm cov khoom siv! Thaum cov ntaub ntawv tsim kho raug daj, cov khoom hloov tshiab yuav tsum tau hloov sai li sai tau.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-20-2023