Cellulose Ether hauv Ntawv Kev Lag Luam

Daim ntawv no qhia txog hom, kev npaj, cov yam ntxwv ntawm kev ua tau zoo thiab daim ntawv thov txheej txheem ntawm cellulose ethers hauv kev lag luam papermaking, tso rau pem hauv ntej qee yam tshiab ntawm cellulose ethers nrog txoj kev loj hlob, thiab sib tham txog lawv daim ntawv thov thiab kev loj hlob qauv hauv papermaking.

Cov lus tseem ceeb:cellulose ether; kev ua tau zoo; ntawv kev lag luam

Cellulose yog lub ntuj polymer compound, nws cov qauv tshuaj yog polysaccharide macromolecule nrog anhydrous.β-glucose ua lub hauv paus nplhaib, thiab txhua lub nplhaib hauv paus muaj pawg thawj hydroxyl thiab ib pawg hydroxyl theem nrab. Los ntawm nws cov tshuaj hloov kho, muaj ntau cov cellulose derivatives tuaj yeem tau txais. Txoj kev npaj ntawm cellulose ether yog react cellulose nrog NaOH, tom qab ntawd nqa tawm etherification cov tshuaj tiv thaiv nrog ntau yam functional reactants xws li methyl chloride, ethylene oxide, propylene oxide, thiab lwm yam, thiab ces ntxuav cov by-product ntsev thiab ib co cellulose sodium kom tau. cov khoom. Cellulose ether yog ib qho tseem ceeb derivatives ntawm cellulose, uas tuaj yeem siv dav hauv cov tshuaj thiab kev tu cev, kev lag luam tshuaj txhua hnub, papermaking, zaub mov, tshuaj, kev tsim kho, khoom siv thiab lwm yam lag luam. Nyob rau hauv xyoo tas los no, cov teb chaws txawv teb chaws tau txuas qhov tseem ceeb rau nws txoj kev tshawb fawb, thiab ntau qhov kev ua tiav tau ua tiav hauv cov kev tshawb fawb yooj yim, siv cov txiaj ntsig zoo, thiab kev npaj. Nyob rau hauv xyoo tas los no, qee cov neeg nyob hauv Suav teb tau maj mam pib koom nrog hauv kev tshawb fawb txog qhov no, thiab tau pib ua tiav qee qhov txiaj ntsig hauv kev xyaum tsim khoom. Yog li ntawd, kev txhim kho thiab kev siv cellulose ether plays lub luag haujlwm tseem ceeb hauv kev siv cov khoom siv hluav taws xob txuas ntxiv mus ntxiv thiab txhim kho cov ntawv zoo thiab kev ua haujlwm. Nws yog ib hom tshiab ntawm papermaking additives tsim nyog tsim.

1. Kev faib tawm thiab kev npaj ntawm cellulose ethers

Kev faib tawm ntawm cellulose ethers feem ntau muab faib ua 4 pawg raws li ionicity.

1.1 Nonionic Cellulose Ether

Tsis yog-ionic cellulose ether feem ntau yog cellulose alkyl ether, thiab nws txoj kev npaj yog los teb cov cellulose nrog NaOH, thiab tom qab ntawd ua cov tshuaj tiv thaiv etherification nrog ntau yam kev ua haujlwm monomers xws li monochloromethane, ethylene oxide, propylene oxide, thiab tom qab ntawd tau txais los ntawm kev ntxuav. Cov khoom siv ntsev thiab cellulose sodium, feem ntau suav nrog methyl cellulose ether, methyl hydroxyethyl cellulose ether, methyl hydroxypropyl cellulose ether, hydroxyethyl cellulose ether, cyanoethyl Cellulose ether thiab hydroxybutyl cellulose ether yog dav siv.

1.2 Anionic cellulose ether

Anionic cellulose ethers feem ntau yog sodium carboxymethyl cellulose thiab sodium carboxymethyl hydroxyethyl cellulose. Txoj kev npaj yog los ua cov cellulose nrog NaOH thiab tom qab ntawd nqa tawm ether nrog chloroacetic acid, ethylene oxide thiab propylene oxide. Cov tshuaj tiv thaiv, thiab tom qab ntawd tau los ntawm kev ntxuav cov khoom siv ntsev thiab sodium cellulose.

1.3 Cationic Cellulose Ether

Cationic cellulose ethers feem ntau muaj xws li 3-chloro-2-hydroxypropyltrimethylammonium chloride cellulose ether, uas yog npaj los ntawm reacting cellulose nrog NaOH thiab ces reacting nrog cationic etherifying tus neeg saib xyuas 3-chloro-2-hydroxypropyl Trimethyl ammonium chloride los yog etherification cov tshuaj tiv thaiv nrog ethylene oxide thiab ethylene oxide. thiab ces tau los ntawm kev ntxuav cov by-product ntsev thiab sodium cellulose.

1.4 Zwitterionic Cellulose Ether

Cov saw molecular ntawm zwitterionic cellulose ether muaj ob pawg anionic thiab cationic pawg. Nws txoj kev npaj yog los ua cov cellulose nrog NaOH thiab tom qab ntawd hnov ​​​​mob nrog monochloroacetic acid thiab cationic etherification tus neeg sawv cev 3-chloro-2-hydroxypropyl Trimethylammonium chloride yog etherified, thiab tom qab ntawd tau los ntawm kev ntxuav cov khoom siv ntsev thiab sodium cellulose.

2. Kev ua tau zoo thiab cov yam ntxwv ntawm cellulose ether

2.1 Zaj duab xis tsim thiab adhesion

Lub etherification ntawm cellulose ether muaj kev cuam tshuam zoo rau nws cov yam ntxwv thiab cov khoom, xws li solubility, film-forming peev xwm, daim ntawv cog lus lub zog thiab ntsev tsis kam. Cellulose ether muaj zog txhua yam, yoog raws, ua haujlwm kub thiab txias, thiab muaj kev sib raug zoo nrog ntau yam resins thiab plasticizers, thiab tuaj yeem siv los ua cov yas, zaj duab xis, varnishes, adhesives, latex thiab tshuaj txheej cov ntaub ntawv, thiab lwm yam.

2.2 Solubility

Cellulose ether muaj cov dej zoo solubility vim muaj cov pab pawg polyhydroxyl, thiab muaj cov kuab tshuaj sib txawv rau cov kuab tshuaj organic raws li cov khoom sib txawv. Methylcellulose yog soluble hauv dej txias, insoluble hauv dej kub, thiab tseem soluble hauv qee cov kuab tshuaj; methyl hydroxyethyl cellulose yog soluble hauv dej txias, insoluble hauv dej kub thiab cov kuab tshuaj organic. Txawm li cas los xij, thaum lub aqueous tov ntawm methylcellulose thiab methylhydroxyethylcellulose yog rhuab, methylcellulose thiab methylhydroxyethylcellulose yuav precipitate. Methyl cellulose yog precipitated ntawm 45-60°C, thaum nag lossis daus kub ntawm cov etherified methyl hydroxyethyl cellulose yog nce mus rau 65-80°C. Thaum qhov kub thiab txias, cov precipitate redissolves. Hydroxyethylcellulose thiab sodium carboxymethylcellulose yog soluble hauv dej ntawm qhov kub thiab txias thiab insoluble hauv cov kuab tshuaj organic (nrog qee qhov kev zam). Siv cov cuab yeej no, ntau yam roj repellants thiab cov ntaub ntawv soluble zaj duab xis tuaj yeem npaj tau.

2.3 Thickening

Cellulose ether yog yaj nyob rau hauv dej nyob rau hauv daim ntawv ntawm colloid, nws viscosity nyob ntawm lub degree ntawm polymerization ntawm cellulose ether, thiab cov tshuaj muaj hydrated macromolecules. Vim yog qhov entanglement ntawm macromolecules, tus cwj pwm ntws ntawm cov kev daws teeb meem txawv ntawm cov kua Newtonian, tab sis nthuav tawm tus cwj pwm uas hloov nrog lub zog shear. Vim yog cov qauv macromolecular ntawm cellulose ether, viscosity ntawm cov tshuaj nce sai nrog qhov nce ntawm cov concentration thiab txo qis nrog qhov kub thiab txias. Raws li nws cov yam ntxwv, cellulose ethers xws li carboxymethyl cellulose thiab hydroxyethyl cellulose tuaj yeem siv los ua cov thickeners rau cov tshuaj niaj hnub, cov dej tuav cov neeg ua haujlwm rau cov ntawv txheej, thiab cov thickeners rau architectural coatings.

2.4 Degradability

Thaum cellulose ether yaj nyob rau hauv cov dej theem, cov kab mob yuav loj hlob, thiab kev loj hlob ntawm cov kab mob yuav ua rau zus tau tej cov enzyme kab mob. Lub enzyme rhuav tshem cov unsubstituted anhydroglucose unit bonds nyob ib sab ntawm cellulose ether, txo cov txheeb ze molecular hnyav ntawm lub polymer. Yog li ntawd, yog tias cov tshuaj cellulose ether aqueous yuav tsum tau khaws cia rau lub sijhawm ntev, cov tshuaj tua kab mob yuav tsum tau ntxiv rau nws, thiab qee yam tshuaj tua kab mob yuav tsum tau noj txawm tias cov cellulose ethers nrog cov tshuaj tua kab mob.

3. Kev siv cov cellulose ether hauv kev lag luam ntawv

3.1 Daim ntawv txhawb zog

Piv txwv li, CMC tuaj yeem siv ua fiber ntau dispersant thiab ib daim ntawv ntxiv dag zog, uas tuaj yeem muab ntxiv rau hauv cov ntaub so ntswg. Txij li thaum sodium carboxymethyl cellulose muaj tib nqi raws li cov ntaub so ntswg thiab muab tub lim, nws tuaj yeem ua kom qhov sib npaug ntawm fiber ntau. Cov txiaj ntsig kev sib txuas ntawm cov fibers tuaj yeem txhim kho, thiab cov ntsuas lub cev xws li lub zog tensile, tawg lub zog, thiab daim ntawv sib npaug ntawm daim ntawv tuaj yeem txhim kho. Piv txwv li, Longzhu thiab lwm tus siv 100% bleached sulfite ntoo pulp, 20% talcum hmoov, 1% dispersed rosin kua nplaum, kho tus nqi pH mus rau 4.5 nrog txhuas sulfate, thiab siv viscosity siab CMC (viscosity 800 ~ 1200MPA.S) Qhov degree kev hloov pauv yog 0.6. Nws tuaj yeem pom tias CMC tuaj yeem txhim kho lub zog qhuav ntawm daim ntawv thiab kuj tseem txhim kho nws qhov kev loj hlob.

3.2 Surface sizing agent

Sodium carboxymethyl cellulose tuaj yeem siv los ua tus neeg sawv cev ntawm daim ntawv los txhim kho lub zog ntawm daim ntawv. Nws cov nyhuv ntawm daim ntawv thov tuaj yeem ua rau lub zog saum npoo los ntawm kwv yees li 10% piv nrog rau kev siv tam sim no ntawm polyvinyl cawv thiab hloov pauv cov hmoov txhuv nplej siab, thiab qhov ntau npaum li cas tuaj yeem txo los ntawm 30%. Nws yog ib qho kev cog lus zoo tshaj plaws rau kev tsim cov ntaub ntawv, thiab cov khoom siv tshiab no yuav tsum tau ua kom nquag plias. Cationic cellulose ether muaj qhov zoo ntawm qhov loj me dua li cov hmoov txhuv nplej siab cationic. Nws tuaj yeem tsis tsuas yog txhim kho lub zog saum npoo ntawm daim ntawv, tab sis kuj txhim kho cov cwj mem nqus ntawm daim ntawv thiab ua kom cov nyhuv dyeing. Nws kuj yog ib qho pheej yig tus neeg saib xyuas qhov loj me. Mo Lihuan thiab lwm tus siv sodium carboxymethyl cellulose thiab oxidized starch los ua qhov ntsuas qhov ntsuas ntawm daim ntawv thiab cov duab los qhia. Cov txiaj ntsig tau pom tias CMC muaj qhov zoo tagnrho qhov loj me.

Methyl carboxymethyl cellulose sodium muaj qee qhov kev ua tau zoo, thiab carboxymethyl cellulose sodium tuaj yeem siv los ua tus neeg sawv cev ntawm lub cev. Ntxiv rau nws tus kheej sizing degree, cationic cellulose ether kuj tseem siv tau los ua cov ntaub ntawv khaws cia cov lim dej, txhim kho tus nqi tuav ntawm cov fibers zoo thiab muab tub lim, thiab tseem tuaj yeem siv los ua daim ntawv txhawb zog.

3.3 Emulsion Stabilizer

Cellulose ether yog siv dav hauv kev npaj emulsion vim nws cov nyhuv thickening zoo hauv cov kua dej, uas tuaj yeem ua rau kom cov viscosity ntawm emulsion dispersion nruab nrab thiab tiv thaiv emulsion nag lossis daus thiab stratification. Xws li sodium carboxymethyl cellulose, hydroxyethyl cellulose ether, hydroxypropyl cellulose ether, thiab lwm yam tuaj yeem siv los ua cov stabilizers thiab cov tshuaj tiv thaiv rau anionic dispersed rosin gum, cationic cellulose ether, hydroxyethyl cellulose ether, hydroxypropyl cellulose ether, Basether, thiab lwm yam. ether, thiab lwm yam kuj tseem siv tau los ua cov tshuaj tiv thaiv rau cationic disperse rosin gum, AKD, ASA thiab lwm yam sizing agents. Longzhu et al. siv 100% bleached sulfite ntoo pulp, 20% talcum hmoov, 1% dispersed rosin kua nplaum, kho tus nqi pH rau 4.5 nrog txhuas sulfate, thiab siv ntau dua viscosity CMC (viscosity 800 ~ 12000MPA.S). Qhov degree ntawm kev hloov pauv yog 0.6, thiab nws yog siv rau qhov loj me. Nws tuaj yeem pom los ntawm cov txiaj ntsig tau hais tias qhov ntsuas qhov loj me ntawm cov roj hmab rosin uas muaj CMC tau pom tseeb zoo dua, thiab kev ruaj ntseg ntawm cov rosin emulsion yog qhov zoo, thiab cov nqi tuav ntawm cov khoom siv roj hmab kuj siab.

3.4 Txheej dej tuav tus neeg sawv cev

Nws yog siv rau txheej thiab ua cov ntawv txheej binder, cyanoethyl cellulose, hydroxyethyl cellulose, thiab lwm yam. tuaj yeem hloov cov casein thiab ib feem ntawm cov latex, kom cov ntawv luam ntawv tuaj yeem nkag tau yooj yim thiab cov npoo yog qhov tseeb. Carboxymethyl cellulose thiab hydroxyethyl carboxymethyl cellulose ether tuaj yeem siv ua xim dispersant, thickener, dej tuav tus neeg sawv cev thiab stabilizer. Piv txwv li, tus nqi ntawm carboxymethyl cellulose siv los ua cov dej tuav hauv kev npaj cov ntawv coated yog 1-2%.

4. Txoj Kev Loj Hlob ntawm Cellulose Ether siv hauv kev lag luam ntawv

Kev siv tshuaj hloov kho kom tau txais cellulose derivatives nrog cov haujlwm tshwj xeeb yog ib txoj hauv kev zoo los nrhiav kev siv tshiab ntawm lub ntiaj teb cov txiaj ntsig loj tshaj plaws ntawm cov organic teeb meem-cellulose. Muaj ntau ntau hom cellulose derivatives thiab dav zog, thiab cellulose ethers tau siv nyob rau hauv ntau industries vim lawv ua tau zoo heev. Yuav kom ua tau raws li cov kev xav tau ntawm kev lag luam ntawv, kev tsim cov cellulose ether yuav tsum tau them sai sai rau cov hauv qab no:

(1) Tsim ntau yam khoom tshwj xeeb ntawm cellulose ethers haum rau daim ntawv thov kev lag luam, xws li cov khoom siv sib txawv ntawm kev hloov pauv, sib txawv viscosities, thiab sib txawv cov txheeb ze molecular pawg, rau kev xaiv hauv kev tsim cov ntawv sib txawv.

(2) Txoj kev loj hlob ntawm ntau yam tshiab ntawm cellulose ethers yuav tsum tau nce, xws li cationic cellulose ethers haum rau papermaking retention thiab kua dej pab, deg sizing agents, thiab zwitterionic cellulose ethers uas yuav siv tau raws li reinforcing agents los hloov txheej latex Cyanoethyl cellulose ether thiab zoo li ib tug binder.

(3) Txhim kho cov kev tshawb fawb ntawm cov txheej txheem npaj ntawm cellulose ether thiab nws txoj kev npaj tshiab, tshwj xeeb tshaj yog kev tshawb fawb txog kev txo nqi thiab ua kom yooj yim rau cov txheej txheem.

(4) Txhim kho cov kev tshawb fawb ntawm cov khoom ntawm cellulose ethers, tshwj xeeb tshaj yog cov yeeb yaj kiab tsim cov khoom, cov khoom sib txuas thiab cov khoom tuab ntawm ntau cov cellulose ethers, thiab ntxiv dag zog rau kev tshawb fawb theoretical ntawm kev siv cellulose ethers hauv papermaking.