Cellulose ether (CE) yog ib chav kawm ntawm derivatives tau los ntawm kev hloov kho cellulose. Cellulose yog cov khoom tseem ceeb ntawm cov phab ntsa ntawm cov nroj tsuag, thiab cellulose ethers yog cov polymers tsim los ntawm etherification ntawm qee pawg hydroxyl (–OH) hauv cellulose. Lawv tau siv dav hauv ntau qhov chaw xws li cov khoom siv hauv tsev, tshuaj, khoom noj, tshuaj pleev ib ce, thiab lwm yam, thiab tau siv dav hauv ntau yam lag luam vim lawv lub cev thiab tshuaj lom neeg tshwj xeeb thiab ntau yam.
1. Kev faib tawm ntawm cellulose ethers
Cellulose ethers tuaj yeem muab faib ua ntau hom raws li hom kev hloov pauv hauv cov qauv tshuaj. Kev faib ntau tshaj plaws yog nyob ntawm qhov sib txawv ntawm cov neeg hloov pauv. Feem ntau cellulose ethers yog raws li nram no:
Methyl Cellulose (MC)
Methyl cellulose yog tsim los ntawm kev hloov cov hydroxyl ib feem ntawm cellulose molecule nrog methyl (–CH₃). Nws muaj cov thickening zoo, film-forming thiab bonding zog thiab yog feem ntau siv nyob rau hauv lub tsev cov ntaub ntawv, coatings, tshuaj thiab zaub mov industries.
Hydroxypropyl methylcellulose (HPMC)
Hydroxypropyl methylcellulose yog ib hom cellulose ether, uas yog siv dav hauv cov khoom siv hauv tsev, tshuaj, tshuaj txhua hnub thiab zaub mov vim nws cov dej zoo dua solubility thiab tshuaj stability. HPMC yog nonionic cellulose ether nrog cov khoom ntawm dej tuav, thickening thiab stability.
Carboxymethyl cellulose (CMC)
Carboxymethyl cellulose yog anionic cellulose ether tsim los ntawm kev qhia carboxymethyl (–CH₂COOH) pawg rau hauv cellulose molecules. CMC muaj cov dej solubility zoo heev thiab feem ntau yog siv los ua cov thickener, stabilizer thiab suspending agent. Nws ua lub luag haujlwm tseem ceeb hauv zaub mov, tshuaj thiab tshuaj pleev ib ce.
Ethyl cellulose (EC)
Ethyl cellulose yog tau los ntawm kev hloov cov pab pawg hydroxyl hauv cellulose nrog ethyl (–CH₂CH₃). Nws muaj hydrophobicity zoo thiab feem ntau yog siv los ua cov yeeb yaj kiab txheej thiab tswj cov khoom tso tawm hauv kev lag luam kws tshuaj.
2. Lub cev thiab tshuaj muaj zog ntawm cellulose ethers
Lub cev thiab tshuaj lom neeg ntawm cellulose ethers yog ze ze rau yam xws li hom cellulose ether, hom kev hloov pauv thiab qib ntawm kev hloov pauv. Nws cov khoom tseem ceeb muaj xws li cov hauv qab no:
Dej solubility thiab solubility
Feem ntau cov cellulose ethers muaj cov dej zoo solubility thiab tuaj yeem yaj hauv dej txias lossis dej kub los tsim cov kua dej ntshiab colloidal. Piv txwv li, HPMC, CMC, thiab lwm yam tuaj yeem yaj sai sai hauv dej los tsim cov tshuaj viscosity siab, uas yog siv dav hauv daim ntawv thov scenarios nrog rau kev ua haujlwm xws li thickening, ncua kev kawm ntawv, thiab kev tsim zaj duab xis.
Thickening thiab film-forming zog
Cellulose ethers muaj cov khoom thickening zoo heev thiab tuaj yeem ua kom cov viscosity ntawm aqueous daws tau zoo. Piv txwv li, ntxiv HPMC rau cov khoom siv hauv tsev tuaj yeem txhim kho cov yas thiab kev ua haujlwm ntawm mortar thiab txhim kho cov khoom tiv thaiv sagging. Nyob rau tib lub sijhawm, cellulose ethers muaj cov yeeb yaj kiab zoo thiab tuaj yeem tsim cov yeeb yaj kiab tiv thaiv zoo ib yam ntawm cov khoom siv, yog li lawv tau siv dav hauv cov txheej txheem tshuaj thiab tshuaj pleev xim.
Dej tuav thiab stability
Cellulose ethers kuj muaj peev xwm khaws dej zoo, tshwj xeeb tshaj yog nyob rau hauv cov khoom siv hauv tsev. Cellulose ethers feem ntau yog siv los txhim kho cov dej tuav ntawm cov cement mortar, txo qhov tshwm sim ntawm mortar shrinkage tawg, thiab txuas lub neej kev pab cuam ntawm mortar. Hauv cov khoom noj khoom haus, CMC kuj tseem siv los ua tus humectant kom ncua cov zaub mov kom qhuav.
Tshuaj stability
Cellulose ethers qhia zoo tshuaj stability nyob rau hauv acid, alkali thiab electrolyte daws, thiab muaj peev xwm tswj tau lawv cov qauv thiab ua hauj lwm nyob rau hauv ib tug ntau yam ntawm complex tshuaj ib puag ncig. Qhov no tso cai rau lawv siv ntau yam kev lag luam yam tsis muaj kev cuam tshuam los ntawm lwm yam tshuaj.
3. Cov txheej txheem ntau lawm ntawm cellulose ether
Kev tsim cov cellulose ether feem ntau yog npaj los ntawm etherification cov tshuaj tiv thaiv ntawm ntuj cellulose. Cov txheej txheem txheej txheem muaj xws li kev kho alkalization ntawm cellulose, etherification cov tshuaj tiv thaiv, purification, thiab lwm yam.
Kev kho alkalization
Ua ntej, ntuj cellulose (xws li paj rwb, ntoo, thiab lwm yam) yog alkalized los hloov cov hydroxyl nyob rau hauv cellulose rau hauv cov dej cawv ntsev heev.
Etherification cov tshuaj tiv thaiv
Cov cellulose tom qab alkalization reacts nrog tus neeg sawv cev etherifying (xws li methyl chloride, propylene oxide, thiab lwm yam) los tsim cellulose ether. Nyob ntawm cov tshuaj tiv thaiv, ntau hom cellulose ethers tuaj yeem tau txais.
Purification thiab ziab
Cov cellulose ether generated los ntawm cov tshuaj tiv thaiv yog purified, ntxuav thiab qhuav kom tau ib tug hmoov los yog granular khoom. Lub purity thiab lub cev muaj zog ntawm cov khoom kawg tuaj yeem tswj tau los ntawm kev ua haujlwm tom ntej.
4. Daim ntawv thov teb ntawm cellulose ether
Vim yog lub cev thiab tshuaj lom neeg tshwj xeeb ntawm cellulose ethers, lawv tau siv dav hauv ntau lub lag luam. Lub ntsiab daim ntawv thov teb yog raws li nram no:
Cov khoom siv hauv tsev
Hauv kev tsim cov khoom siv hauv tsev, cellulose ethers feem ntau yog siv los ua cov thickeners thiab dej tuav cov neeg ua haujlwm rau cov cement mortar thiab gypsum-based khoom. Cellulose ethers xws li HPMC thiab MC tuaj yeem txhim kho kev tsim kho ntawm mortar, txo cov dej poob, thiab yog li txhim kho adhesion thiab tawg tsis kam.
Tshuaj kho mob
Hauv kev lag luam kws tshuaj, cellulose ethers tau dav siv los ua cov tshuaj pleev xim rau cov tshuaj, cov nplaum rau cov ntsiav tshuaj, thiab cov ntaub ntawv tswj-tso tawm. Piv txwv li, HPMC feem ntau yog siv los npaj cov tshuaj yeeb yaj kiab coatings thiab muaj cov txiaj ntsig zoo-tso tawm.
Khoom noj khoom haus
CMC feem ntau yog siv los ua cov thickener, emulsifier, thiab stabilizer hauv kev lag luam khoom noj. Nws yog dav siv hauv dej haus, khoom noj siv mis, thiab cov khoom ci, thiab tuaj yeem txhim kho saj thiab moisturizing khoom ntawm cov khoom noj.
Tshuaj pleev ib ce thiab tshuaj txhua hnub
Cellulose ethers yog siv los ua cov thickeners thiab emulsifiers thiab stabilizers hauv cov tshuaj pleev ib ce thiab cov tshuaj niaj hnub, uas tuaj yeem muab kev sib luag zoo thiab kev ntxhib los mos. Piv txwv li, HPMC feem ntau siv rau hauv cov khoom xws li tshuaj txhuam hniav thiab tshuaj zawv plaub hau kom lawv muaj kev xav zoo thiab muaj kev cuam tshuam ruaj khov.
Txheej txheej
Hauv kev lag luam coatings, cellulose ethers yog siv los ua cov thickeners, zaj duab xis qub, thiab tshem tawm cov neeg ua haujlwm, uas tuaj yeem txhim kho kev tsim kho ntawm cov txheej txheem, txhim kho qib, thiab muab cov xim zoo nkauj zoo nkauj.
5. Kev txhim kho yav tom ntej ntawm cellulose ethers
Nrog rau qhov kev thov ntau ntxiv rau kev tiv thaiv ib puag ncig, cellulose ether, raws li cov txiaj ntsig ntawm cov khoom siv txuas ntxiv dua tshiab, muaj kev loj hlob dav dav. Nws biodegradability, renewability thiab versatility ua rau nws yuav tsum tau siv dav nyob rau hauv lub teb ntawm cov ntaub ntawv ntsuab, degradable cov ntaub ntawv thiab cov khoom ntse yav tom ntej. Tsis tas li ntawd, cellulose ether kuj tseem muaj kev tshawb fawb ntxiv thiab kev txhim kho muaj peev xwm hauv cov khoom muaj nqis ntxiv xws li biomedical engineering thiab cov khoom siv siab heev.
Raws li cov khoom lag luam tseem ceeb, cellulose ether muaj ntau yam ntawm daim ntawv thov nqi. Nrog nws zoo heev thickening, dej tuav, zaj duab xis-tsim thiab zoo tshuaj stability, nws plays ib tug irreplaceable luag hauj lwm nyob rau hauv ntau yam xws li kev tsim kho, tshuaj, thiab zaub mov. Nyob rau hauv lub neej yav tom ntej, nrog kev nce qib ntawm cov thev naus laus zis thiab kev txhawb nqa ntawm kev tiv thaiv ib puag ncig, daim ntawv thov kev cia siab ntawm cellulose ether yuav dav dua thiab ua kom muaj txiaj ntsig ntau dua los txhawb txoj kev loj hlob ntawm ntau yam kev lag luam.
Post lub sij hawm: Sep-24-2024