Reactive dyes yog cov feem ntau siv dyes nyob rau hauv paj rwb dyeing, thiab lawv noj kuj nce, thiab cov qauv no yuav tsum nyob twj ywm nyob rau hauv ob peb xyoos tom ntej no. Reactive dyes yog nrov vim lawv cov nqi nruab nrab, cov xim zoo nkauj, thiab cov xim tsim nyog. Nws tsuas yog qhov tsis zoo yog hydrolysis ntawm dyes
Lub ntsiab lus ntawm hydrolysis
Feem ntau cov dyes yog tsau ntawm paj rwb nyob rau hauv alkaline tej yam kev mob, thiab alkalinity no txhawb cov tshuaj tiv thaiv ntawm cov dye nrog dej, ua rau nws deactivated. Deactivated dyes, piv txwv li hydrolyzed dyes, tsis tuaj yeem hnov mob nrog paj rwb, ua rau muaj kev cuam tshuam loj heev ntawm cov xim. Cov hydrolyzed dyes lub cev ua raws li cov substrate kom txog thaum lawv raug tshem tawm thaum lub sij hawm ntxuav, yog li ua rau muaj teeb meem ntxuav ceev. Tsis tas li ntawd, hydrolyzed dyes kuj ntws mus rau hauv cov kua khib nyiab, ua rau muaj kuab paug ntau ntxiv.
Reactive dyes dye cellulose fiber substrates nyob rau hauv peb theem:
Dyeing nyob rau hauv nruab nrab nruab nrab nrog ntsev los yog Yuanming hmoov.
Cov dyeing dyeing yog tsau tom qab ntxiv alkali, thiab covalent daim ntawv cog lus yog tsim ntawm cov dyeing thiab fiber.
Ua tib zoo ntxuav tawm loosely adhering dyestuffs ntawm lossis hauv cov ntaub.
Qhov thib peb theem uas tau hais los saum no yog qhov tsim nyog heev. Qhov no yog vim hais tias feem ntau ntawm cov reactive dyes nyob rau hauv lub dyebath yog dyed nrog fibers, thiab ib co ntawm lawv reacts nrog dej nyob rau hauv alkaline tej yam kev mob, poob lawv reactivity nrog fibers, thiab yog li muaj tsawg affinity nrog fibers. Yog tias cov kauj ruam no ua tsis tau zoo, vim tias muaj cov khoom siv hydrolyzed, kev ntxuav ceev ntawm cov khoom dyed yuav tsis zoo; thaum cov dyes uas hnov mob nrog cov fibers yuav muaj siab ceev ceev.
Cov tshuaj tiv thaiv ntawm reactive dyes nrog dej tsis yog tib yam cuam tshuam rau cov txiaj ntsig ntawm dyeing. Daim ntawv thov kev ua tau zoo ntawm cov dye kuj tseem cuam tshuam nrog rau cov hauv qab no, xws li kev ruaj ntseg ntawm cov xim, kev ruaj ntseg ntawm cov tshuaj padding lossis luam ntawv muab tshuaj, thiab kev hloov pauv ntawm cov xim reactive dye concentration nyob rau hauv lub dye formulation thaum thermal dissolution.
Lub hydrolytic decomposition ntawm dyes tshwm sim los ntawm lub sijhawm ntawm kev tsim khoom thiab txuas ntxiv thaum ziab thiab sib tsoo. Qhov degree ntawm dye hydrolysis nyob ntawm cov pawg reactive thiab chromophores hauv nws cov molecule.
Hydrolyzed dyes tsuas yog cov atoms tsis ruaj khov lossis pab pawg hauv cov khoom qub reactive dyes yog hloov los ntawm hydroxyl pawg, thiab lawv cov diffusion thiab adsorption zog zoo ib yam li qub reactive dyes, yog li nws yooj yim rau diffuse rau hauv fiber ntau thiab adsorb ntawm nws qhov chaw.
Thaum kawg ntawm alkaline dyeing theem, thaum cov reactive dyes hnov mob nrog dej los yog fibers thiab tag nrho noj, ib tug tshiab tshuav nyiaj li cas yog tsim, uas yog, qhov sib npaug ntawm hydrolyzed dyes nyob rau hauv fiber thiab dyebath. Kev faib tawm ntawm cov tshuaj reactive dyes hauv cov kev daws teeb meem nruab nrab yog qhov zoo sib xws. Nyob rau theem no, cov fibers muaj ib tug loj npaum li cas ntawm chemically khi dyes.
Txhawm rau kom tau txais cov khoom dyed nrog cov ntub dej nrawm, hydrolyzed dyestuffs yuav tsum tau muab tshem tawm ntawm cov fibers thaum lub sij hawm ntxuav dej zaum kawg. Hauv kev dyeing ntawm reactive dyes, kwv yees li 70% ntawm cov dyes yog tsau nyob rau hauv fiber nyob rau hauv nruab nrab, thiab tus so yog nkim los ntawm hydrolysis, thiab tsawg kawg yog 30% ntawm no feem ntawm cov dyes yog siv.
Hauv cov tshuaj tiv thaiv tiag tiag, muaj ntau yam cuam tshuam rau hydrolysis tus nqi ntawm reactive dyes, xws li dye da dej pH, kub, dye concentration thiab electrolyte concentration.
(1) Kev cuam tshuam ntawm pH tus nqi ntawm cov dye da dej Los ntawm kev kawm txog kev sib raug zoo ntawm tus nqi pH ntawm nruab nrab thiab qib ntawm cellulose dissociation, nws tau pom tias cov alkali concentration tsis tuaj yeem nce ntxiv, yog li ntawd tus nqi pH ntawm qhov nruab nrab. daws tau dhau 10-11. Vim hais tias, nyob rau lub sijhawm no, tag nrho cov pab pawg hydroxyl nkag tau hauv cellulose yog ionized, thiab nce pH tus nqi tsuas yog ua rau nws cov hydrolysis.
(2) Kev cuam tshuam ntawm qhov kub thiab txias nce qhov kub yuav ua rau kom muaj zog hydrolysis ntawm reactive dyes.
(3) Cov nyhuv ntawm dye concentration nce qhov concentration ntawm reactive dye nyob rau hauv cov tshuaj yuav txhawb nws coagulation, yog li txo tus nqi hydrolysis.
(4) Cov nyhuv ntawm electrolyte concentration Qhov siab dua cov electrolyte concentration hauv cov dye da dej, ntau dyes yog hydrolyzed.
"Txoj kev tshawb fawb pom tau tias cov reactivity ntawm reactive dyes nrog dej kuj muaj feem xyuam rau cov chromophore nyob rau hauv cov xim molecule, vim hais tias cov chromophore yuav cuam tshuam rau electron huab ntom ntom ntawm cov tshuaj tiv thaiv qhov chaw. center's Lub electron huab ceev nce, yog li txo cov reactivity ntawm reactive dyes nrog dej.