1. Kev txhais thiab ua haujlwm ntawm cov tuab tuab
Cov quav ntxiv uas tuaj yeem ua kom cov xim pleev xim rau cov dej uas muaj xim hlau yog hu ua cov thickeners.
Thickeners ua lub luag haujlwm tseem ceeb hauv kev tsim khoom, chaw cia khoom thiab kev tsim kho cov txheej txheem txheej txheem.
Lub luag haujlwm tseem ceeb ntawm cov thickener yog kom nce viscosity ntawm txheej kom tau raws li cov kev cai ntawm kev siv. Txawm li cas los xij, qhov yuav tsum muaj viscosity los ntawm txheej ntawm cov theem sib txawv txawv. Xws li:
Thaum lub sij hawm cia cov txheej txheem cia, nws yog ntshaw kom muaj lub viscosity siab los tiv thaiv cov xim los ntawm kev sib pauv;
Thaum lub sij hawm tsim kho, nws yog ntshaw kom muaj kev viscirecosity los xyuas kom meej tias cov xim muaj cov xim muaj xim ntau dhau;
Tom qab kev tsim kho, nws cia siab tias lub viscosity tuaj yeem rov qab mus rau lub viscosity siab tom qab lub sijhawm luv luv (qib txheej txheem) los tiv thaiv sagging.
Lub fluidity ntawm cov dej ntws tawm yog tsis yog-Newton.
Thaum lub pos hniav ntawm cov xim txo qis dua nrog kev nce ntawm shear zog, nws yog hu ua pseudoplastic kua, thiab feem ntau ntawm cov xim yog pseudoplastic kua.
Thaum tus cwj pwm ntws ntawm cov kua pseudoplastic kua muaj feem xyuam rau nws keeb kwm, uas yog, nws yog lub sijhawm-nyob, nws yog hu ua lub thixotrotropic kua.
Thaum kev tsim cov txheej txheem tsim, peb ib txwm ua kom pom cov txheej txheej thixotropic, xws li ntxiv cov tshuaj ntxiv.
Thaum lub thixotrostropy ntawm txheej yog qhov tsim nyog, nws tuaj yeem daws qhov kev tsis sib haum xeeb ntawm cov txheej txheem ntau yam ntawm cov xim sib txawv ntawm cov txheej txheem sib txawv ntawm cov khoom siv, thiab theem kev tsim kho.
Qee cov thickeners muaj peev xwm ntxiv cov xim uas muaj siab, yog li ntawd nws muaj qhov sib txawv ntawm cov xim lossis tsheb thauj mus los), thiaj li tiv thaiv cov xim hauv cov xim los ntawm kev sib tw. Thiab nyob rau hauv lub siab shear tus nqi (xws li txheej txheem txheej txheem), nws muaj cov viscosity txiav, kom cov txheej muaj txaus ntws thiab theem.
Thixotropy yog sawv cev los ntawm Thixotropic Index TI thiab ntsuas los ntawm Brookfield Sporepus.
Ti = Viscosity (ntsuas ntawm 6R / min) / viscosity (ntsuas ntawm 60r / min)
2. Hom tuab thiab lawv cov teebmeem ntawm cov txheej txheej
(1) Hom nyob rau hauv cov nqe lus ntawm cov tshuaj muaj kuab lom, thickeners tau muab faib ua ob pawg: organic thiab inorganic.
Inorganic hom muaj xws li bentonite, txhuas cov hom me me, cov organic cellulate, acrylic acrryliccer lossis copolymer thiab polyurethane thiab lwm yam.
Los ntawm qhov kev pom ntawm cov kev cuam tshuam ntawm cov khoom ntawm cov txheej txheem ntawm cov txheej txheem, thickeners tau muab faib ua thixotropic thickeners thiab cov phooj ywg thickeners. Hais txog kev ua tau zoo, tus nqi ntawm cov tuab yuav tsum tsawg dua thiab cov nyhuv tuab yog qhov zoo; Nws tsis yooj yim yuav tsum tau yaig los ntawm cov enzymes; Thaum ntsuas kub lossis phot tus nqi ntawm cov txheej txheem hloov pauv, cov viscosity ntawm txheej yuav tsis raug txo qis, thiab cov xim xim thiab cov tub lim khoom yuav tsis muaj nplaim taws. ; Kev khaws cia zoo; Cov dej zoo khaws cia, tsis muaj qhov pom tseeb ua npuas ncauj thiab tsis muaj kev cuam tshuam zoo rau kev ua yeeb yam ntawm cov yeeb yaj kiab txheej.
①Cellulose thalener
Lub cellulose thickeners siv nyob rau hauv cov txheej me me yog feem ntau methylcellulose, hydroxyethylcellulose thiab hydroxyprropencethylcethylpcellulose, thiab ob qho kawg siv ntau dua.
Hydroxyethyl cellulose yog cov khoom tau los ntawm hloov cov pawg hydroxyl ntawm cov roj qab zib ntawm cov pab pawg ntuj ntawm hydroxyethyl pawg. Cov khoom lag luam tshwj xeeb thiab qauv ntawm cov khoom lag luam yog tsuas yog muaj kev sib txawv raws li cov degree ntawm hloov chaw thiab viscosity.
Cov ntau yam ntawm hydroxyethyl cellulose tseem muab faib ua ib txwm muaj hom, hom kev faib tawm sai sai. Raws li cov txheej txheem ntawm kev siv yog kev txhawj xeeb, hydroxyethyl cellulose tuaj yeem raug ntxiv ntawm cov txheej txheem ntau lawm. Cov hom nrawm-dispersing tuaj yeem txuas ncaj qha rau hauv daim ntawv ntawm cov hmoov qhuav. Txawm li cas los xij, tus nqi ntawm tus nqi ntawm cov kab ke ua ntej yuav tsum muaj tsawg dua 7, feem ntau yog lub sijhawm txaus rau hauv pH tus nqi qis, thiab tom qab ntawd tus nqi pH tau nce ntxiv kom nws yaj sai. Cov kauj ruam sib xws kuj tseem siv tau los npaj qee qhov kev xav ntawm cov kua nplaum thiab ntxiv rau nws cov txheej txheem txheej txheej.
HydroxyPropyyl methylulose yog cov khoom tau los ntawm kev hloov cov pab pawg hydroxyl ntawm pab pawg muaj me me nrog cov pab pawg me me, thaum lwm qhov hloov los ntawm cov pab pawg hydroxyprropylopyl. Nws cov nyhuv tuab yog ib qho zoo ib yam li ntawm hydroxyethyl cellulose. Thiab nws tiv taus enzymatic degradation, tab sis nws cov dej solubility tsis zoo li tias ntawm hydroxyethyl cellulose, thiab nws muaj qhov tsis zoo ntawm kev loj hlob thaum rhuab. Rau cov npoo-kho hydroxypropyl methylcellulose, nws tuaj yeem txuas ncaj qha ntxiv rau dej thaum siv. Tom qab nplawm thiab dispersing, ntxiv alkaline cov tshuaj xws li dej ammonia los kho tus nqi py rau 8-9, thiab do kom txog thaum tau yaj tag nrho. Rau hydroxypropyl methylulose tsis muaj kev kho deg, nws tuaj yeem ua kom sov nrog chav dej kub, thiab tom qab ntawd txias nrog dej txias lossis dej khov kom yaj nws.
②inorganic thickener
Qhov kev ua kom tuab no tsuas yog qee cov khoom av nplaum qhib, xws li cov nyhuv bentonite, nws tseem muaj kev cuam tshuam zoo, thiab yuav tsis cuam tshuam rau cov dej tsis kam ntawm cov txheej. Tom qab txheej txheej qhuav thiab tsim rau hauv zaj duab xis, nws ua raws li cov muab tub lim rau hauv cov yeeb yaj kiab txheej, thiab nws yuav cuam tshuam qhov tseem ceeb rau kev txheej ntawm txheej.
③ Cov Khoom Siv Hluav Taws Xob Polymer Polymer
Cov khoom siv hluavtaws polymer feem ntau yog siv rau hauv acrylic thiab polyurethane (cuam tshuam thickeners). Acrylic thickeners feem ntau yog acrylic polymers muaj cov roj carboxyl. Hauv dej nrog tus nqi PHY ntawm 8-10, cov carboxyl pab pawg dispociates thiab yuav o tuaj; Thaum tus nqi py ntau dua 10, nws yaj nyob hauv dej thiab poob cov nyhuv tuab, yog li cov nyhuv thickening yog rhiab heev rau tus nqi PH.
Qhov tuab tuab ntawm cov tuab acrylate tuab yog tias nws cov txheej txheem ntawm cov kua yas, uas ua rau cov khoom siv xim av ntawm cov nplais, thiab ua kom cov xim viscosity ntawm cov xim pleev xim. ; Thib ob, o ntawm cov tuab ua rau visce ntawm cov theem dej.
(2) cawv ntawm cov tuab ntawm cov khoom lag luam
Cov nyhuv ntawm hom tuab ntawm rheological cov yam ntxwv ntawm txheej txheej yog li nram no:
Thaum tus nqi ntawm cov tuab tuab ntxiv, cov kob viscosity ntau tshaj, thiab lub viscosity hloov qauv yog ib txwm muaj thaum raug rau sab nraud shear zog.
Nrog cov nyhuv ntawm cov tuab, viscosity ntawm cov xim ua kom nrawm nrawm thaum nws raug rau shear zog, qhia pseudoplasticity.
Siv cov tuab yaj kiab hydrophobically hloov cov ntaub pua tsev (xws li EBS451FQ), ntawm cov viscosity siab, lub viscosity tseem siab dua thaum cov nyiaj yog loj.
Siv cov neeg sib tham polyurethane (xws li WT105A), ntawm cov nqi siab, lub viscosity tseem siab dua thaum cov nyiaj yog loj.
Kev siv acrylic thickeners (xws li ASE60), txawm hais tias cov pallic viscosity nce sai sai thaum cov nyiaj yog loj, viscosity txo sai sai ntawm ib tug ntau dua shear tus nqi.
3. Kev Sib Koom Siab Thickener
(1) thickening mechanism
Cellulose ether thiab alkali-oatable acrylic thickeners tsuas yog thicken rau ntawm cov xim dej hauv cov pa dej hauv cov xim tsis tuaj yeem hloov kho.
Cov phoojywg nrog cov cim hauv qhov uas cuam tshuam los ntawm kev ua kom tuab, lawv kuj tuab ntawm cov koom ua ke, thiab nrog lwm yam hauv cov kab ke. Lub koomhaum no ua rau lub siab ua haujlwm ntawm tus nqi siab thiab rov ua haujlwm ntawm cov nqi shear tsawg, tso cai rau kev ntseeg ntawm cov txheej txheem kom hloov kho.
Cov txheej txheem tuab ntawm cov neeg sib cav sib ceg yog tias cov pab pawg hydrophilic hauv cov qauv hydrophilic, yog li nws muaj cov yam ntxwv ntawm surfactant molecules. Xwm. Xws li thickener molecules tsis tuaj yeem tsuas yog hydrate thiab o tuaj yeem ua kom tuab ntawm nws cov kev daws teeb meem ntau dua li muaj nuj nqis. Lub micelles tuaj yeem txuam nrog cov polymer hais ntawm cov emulsion thiab cov qauv sib txuas lus, thiab muaj kev sib txuas lus thiab ua kom cov viscosity ntawm lub system.
Dab tsi tseem ceeb tshaj plaws yog tias cov koomhaum no yog nyob rau hauv ib qho kev sib npaug ntawm cov kev sib npaug, thiab cov koom haum sib npaug, yog li cov txheej txheem sab nraud, yog li ntawd cov txheej txheem qib. Ib qho ntxiv, txij li lub Molecule muaj ob peb micelles, tus qauv no txo cov nyiam dej molecules molecules morrate thiab yog li nce lub hom phiaj ua aqueous.
(2) Lub luag haujlwm hauv cov txheej txheem txheej txheem
Feem ntau ntawm cov koom ua ke thickeners yog polyurethanes, thiab lawv cov kev txiav txim siab ntawm polyacrylic nrog qhov hnyav molecular hnyav ntawm 105-106. Vim tias qhov hnyav me me, qhov ua tau zoo ntau ntxiv tom qab kev nkhaus yog tsawg dua, yog li nws viscosity nkhaus yog forratter tshaj qhov uas tsis muaj kev sib raug zoo thickeners.
Vim tias qhov hnyav molecular hnyav ntawm cov neeg sib cav ua ke, nws cov nyhuv sib xyaw nyob rau theem dej tsis yog qhov tseem ceeb. Nyob rau hauv qis dua shear tus nqi ntau yam, kev koom tes hloov dua siab nruab nrab ntawm cov molecules, tag nrho cov txheej txheem kev raug tshem tawm ntawm cov neeg raug tshem tawm ntawm cov neeg viscosity ntawm kev discersion ntawm nruab nrab (dej). Yog li ntawd, cov neeg ua ke thickener ua rau cov xim tha xim ua ke ua rau cov xim thau dej uas tsis pom meej thaum nws nyob hauv thaj av qis shear.
Cov phoojywg nrog cov thickenters ntau ntxiv rau lub zog muaj peev xwm ntawm cov molecules vim yog cov koom nrog hauv cov theem dispersed. Nyob rau hauv txoj kev no, xav tau lub zog ntau dua los ua kom tawg rau cov molecules ntawm siab shear tus nqi, thiab kom lub kaw lus ua kom muaj ntau dua shear tus nqi ntawm cov siab sib tw. Pom tseeb viscosity. Qhov siab dua-shear viscosity thiab qis-shear viscosity tuaj yeem ua rau cov xim tuab ntawm cov xim, uas yog, ob lub thickeners tuaj yeem hloov kho kom zoo ntawm cov xim huv. Kuj tsis paub meej ua tau zoo, kom tau raws li cov kev cai ua kom tiav ntawm cov yeeb yaj kiab tuab thiab txheej zaj duab xis thiab txheej zaj duab xis txaus.
Lub Sijhawm Post: Nov-24-2022