Cellulose etheryog ib qho polymer compound nrog ib qho ether qauv ua los ntawm cellulose. Txhua lub glucosyl nplhaib hauv cellulose macromolecule muaj peb pawg hydroxyl, thawj pawg hydroxyl ntawm lub thib rau carbon atom, thib ob pawg hydroxyl ntawm thib ob thiab thib peb carbon atoms, thiab hydrogen hauv hydroxyl pawg hloov los ntawm hydrocarbon pawg los tsim cellulose ether derivatives yam. Nws yog ib yam khoom uas hydrogen ntawm hydroxyl pawg hauv cellulose polymer hloov los ntawm hydrocarbon pawg. Cellulose yog ib qho polyhydroxy polymer compound uas tsis yaj lossis yaj. Tom qab etherification, cellulose yog soluble hauv dej, dilute alkali kua thiab organic solvent, thiab muaj thermoplasticity.
Cellulose yog ib qho polyhydroxy polymer compound uas tsis yaj thiab tsis yaj. Tom qab etherification, cellulose yog soluble hauv dej, dilute alkali kua thiab organic solvent, thiab muaj thermoplasticity.
1. Xwm Txheej:
Qhov solubility ntawm cellulose tom qab etherification hloov pauv ntau heev. Nws tuaj yeem yaj rau hauv dej, dilute acid, dilute alkali lossis organic solvent. Qhov solubility feem ntau nyob ntawm peb yam: (1) Cov yam ntxwv ntawm cov pab pawg uas tau qhia hauv cov txheej txheem etherification, qhov qhia loj dua pawg, qhov solubility qis dua, thiab qhov muaj zog dua polarity ntawm pawg qhia, qhov yooj yim dua cellulose ether yog yaj rau hauv dej; (2) Qib ntawm kev hloov pauv thiab kev faib tawm ntawm cov pab pawg etherified hauv macromolecule. Feem ntau cellulose ethers tsuas yog yaj rau hauv dej nyob rau hauv qee qib ntawm kev hloov pauv, thiab qib ntawm kev hloov pauv yog ntawm 0 thiab 3; (3) Qib ntawm polymerization ntawm cellulose ether, qib siab dua ntawm polymerization, qhov tsawg dua soluble; Qib qis dua ntawm kev hloov pauv uas tuaj yeem yaj rau hauv dej, qhov dav dua. Muaj ntau hom cellulose ethers nrog kev ua tau zoo heev, thiab lawv tau siv dav hauv kev tsim kho, cement, roj av, khoom noj, textile, tshuaj ntxuav tes, xim, tshuaj, ntawv thiab cov khoom siv hluav taws xob thiab lwm yam lag luam.
2. Tsim Kho:
Tuam Tshoj yog lub ntiaj teb tus tsim khoom loj tshaj plaws thiab cov neeg siv khoom ntawm cellulose ether, nrog rau qhov nruab nrab txhua xyoo kev loj hlob ntawm ntau dua 20%. Raws li cov ntaub ntawv pib, muaj txog 50 lub tuam txhab tsim khoom cellulose ether hauv Suav teb, lub peev xwm tsim khoom ntawm kev lag luam cellulose ether tau tshaj 400,000 tons, thiab muaj txog 20 lub tuam txhab nrog ntau dua 10,000 tons, feem ntau faib hauv Shandong, Hebei, Chongqing thiab Jiangsu. , Zhejiang, Shanghai thiab lwm qhov chaw.
3. Xav tau:
Xyoo 2011, Tuam Tshoj lub peev xwm tsim khoom CMC yog li ntawm 300,000 tons. Nrog rau qhov kev thov kom muaj cov cellulose ethers zoo hauv kev lag luam xws li tshuaj, khoom noj, thiab tshuaj txhua hnub, qhov kev thov hauv tsev rau lwm cov khoom cellulose ether uas tsis yog CMC tab tom nce ntxiv. , lub peev xwm tsim khoom ntawm MC / HPMC yog li ntawm 120,000 tons, thiab ntawm HEC yog li ntawm 20,000 tons. PAC tseem nyob rau theem kev txhawb nqa thiab daim ntawv thov hauv Suav teb. Nrog rau kev txhim kho ntawm cov chaw roj loj hauv hiav txwv thiab kev txhim kho cov ntaub ntawv tsim kho, khoom noj, tshuaj lom neeg thiab lwm yam lag luam, qhov ntau thiab thaj chaw ntawm PAC tab tom nce thiab nthuav dav txhua xyoo, nrog rau lub peev xwm tsim khoom ntau dua 10,000 tons.
4. Kev faib tawm:
Raws li kev faib tawm cov qauv tshuaj ntawm cov tshuaj hloov pauv, lawv tuaj yeem muab faib ua anionic, cationic thiab nonionic ethers. Nyob ntawm tus neeg sawv cev etherification siv, muaj methyl cellulose, hydroxyethyl methyl cellulose, carboxymethyl cellulose, ethyl cellulose, benzyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose cellulose, cyanoethyl cellulose, benzyl cyanoethyl cellulose, carboxymethyl hydroxyethyl cellulose thiab phenyl cellulose, thiab lwm yam. Methyl cellulose thiab ethyl cellulose muaj txiaj ntsig zoo dua.
Methylcellulose:
Tom qab cov paj rwb ua kom zoo lawm raug kho nrog alkali, cellulose ether raug tsim los ntawm ntau qhov kev sib xyaw nrog methane chloride ua tus neeg sawv cev etherification. Feem ntau, qib kev hloov pauv yog 1.6 ~ 2.0, thiab qhov solubility kuj txawv nrog ntau qib kev hloov pauv. Nws yog rau cov cellulose ether uas tsis yog ionic.
(1) Methylcellulose yaj tau hauv dej txias, thiab nws yuav nyuaj rau yaj hauv dej kub. Nws cov kua dej ruaj khov heev hauv pH = 3 ~ 12. Nws muaj kev sib raug zoo nrog cov hmoov txhuv nplej siab, cov roj hmab guar, thiab lwm yam thiab ntau yam surfactants. Thaum qhov kub ncav cuag qhov kub gelation, gelation tshwm sim.
(2) Qhov khaws dej ntawm methyl cellulose nyob ntawm nws qhov ntxiv ntau npaum li cas, viscosity, qhov loj me ntawm cov khoom me me thiab qhov nrawm ntawm kev yaj. Feem ntau, yog tias qhov ntxiv ntau npaum li cas, qhov zoo me me, thiab qhov viscosity loj, qhov nrawm ntawm kev khaws dej siab. Ntawm lawv, qhov nrawm ntawm kev ntxiv muaj qhov cuam tshuam loj tshaj plaws rau qhov nrawm ntawm kev khaws dej, thiab qib ntawm viscosity tsis ncaj qha rau qib ntawm kev khaws dej. Qhov nrawm ntawm kev yaj feem ntau nyob ntawm qib ntawm kev hloov pauv ntawm qhov chaw ntawm cov khoom me me cellulose thiab qhov nrawm ntawm cov khoom me me. Ntawm cov cellulose ethers saum toj no, methyl cellulose thiab hydroxypropyl methyl cellulose muaj qhov nrawm ntawm kev khaws dej siab dua.
(3) Kev hloov pauv ntawm qhov kub thiab txias tuaj yeem cuam tshuam loj heev rau qhov khaws cia dej ntawm methyl cellulose. Feem ntau, qhov kub siab dua, qhov khaws cia dej phem dua. Yog tias qhov kub ntawm cov mortar tshaj 40 ° C, qhov khaws cia dej ntawm methyl cellulose yuav raug txo qis heev, cuam tshuam loj heev rau kev tsim cov mortar.
(4)Methyl cellulosemuaj qhov cuam tshuam loj rau kev ua haujlwm thiab kev sib koom ua ke ntawm cov mortar. Qhov "kev sib txuas" ntawm no yog hais txog lub zog sib txuas uas hnov ntawm tus neeg ua haujlwm lub cuab yeej thov thiab phab ntsa substrate, uas yog, qhov kev tiv thaiv shear ntawm cov mortar. Qhov kev sib txuas yog siab, qhov kev tiv thaiv shear ntawm cov mortar yog loj, thiab lub zog uas cov neeg ua haujlwm xav tau hauv cov txheej txheem ntawm kev siv kuj loj, thiab kev ua haujlwm ntawm cov mortar tsis zoo. Qhov kev sib koom ua ke ntawm methyl cellulose yog nyob rau theem nruab nrab hauv cov khoom cellulose ether.
Hydroxypropylmethylcellulose:
Hydroxypropyl methylcellulose yog ib hom cellulose uas nws cov zis thiab kev noj nce sai. Nws yog ib qho cellulose sib xyaw ether uas tsis yog ionic ua los ntawm paj rwb zoo tom qab alkalization, siv propylene oxide thiab methyl chloride ua tus neeg sawv cev etherification, los ntawm ntau yam kev tshuaj tiv thaiv. Qhov degree ntawm kev hloov pauv feem ntau yog 1.2 ~ 2.0. Nws cov khoom sib txawv nyob ntawm qhov piv ntawm methoxyl cov ntsiab lus rau hydroxypropyl cov ntsiab lus.
(1) Hydroxypropyl methylcellulose yooj yim yaj hauv dej txias, thiab nws yuav ntsib teeb meem hauv kev yaj hauv dej kub. Tab sis nws qhov kub gelation hauv dej kub yog siab dua li ntawm methyl cellulose. Qhov solubility hauv dej txias kuj zoo dua piv rau methyl cellulose.
(2) Qhov viscosity ntawm hydroxypropyl methylcellulose muaj feem cuam tshuam nrog nws qhov hnyav molecular, thiab qhov loj dua qhov hnyav molecular, qhov siab dua qhov viscosity. Kub kuj cuam tshuam rau nws qhov viscosity, thaum kub nce, viscosity txo qis. Txawm li cas los xij, qhov cuam tshuam ntawm nws qhov viscosity siab thiab kub qis dua li ntawm methyl cellulose. Nws cov kua ruaj khov thaum khaws cia rau hauv chav tsev kub.
(3) Qhov khaws cia dej ntawm hydroxypropyl methylcellulose nyob ntawm nws qhov ntxiv, viscosity, thiab lwm yam, thiab nws qhov khaws cia dej nyob rau hauv tib qhov ntxiv yog siab dua li ntawm methyl cellulose.
(4)Hydroxypropyl methylcelluloseNws ruaj khov rau cov kua qaub thiab alkali, thiab nws cov kua dej ruaj khov heev nyob rau hauv qhov ntau ntawm pH = 2 ~ 12. Caustic soda thiab dej txiv qaub tsis muaj feem cuam tshuam rau nws cov kev ua tau zoo, tab sis alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity me ntsis. Hydroxypropyl methylcellulose ruaj khov rau cov ntsev feem ntau, tab sis thaum qhov concentration ntawm cov ntsev yog siab, qhov viscosity ntawm hydroxypropyl methylcellulose kua feem ntau nce.
(5) Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog cov polymer sib xyaw uas yaj tau hauv dej los ua cov kua nplaum uas sib xws thiab viscosity siab dua. Xws li polyvinyl cawv, hmoov txhuv nplej siab ether, cov roj zaub, thiab lwm yam.
(6) Hydroxypropyl methylcellulose muaj kev tiv thaiv enzyme zoo dua li methylcellulose, thiab nws cov kua tsis tshua muaj peev xwm raug rhuav tshem los ntawm cov enzymes dua li methylcellulose.
(7) Qhov nplaum ntawm hydroxypropyl methylcellulose rau kev tsim kho mortar siab dua li ntawm methylcellulose.
Hydroxyethyl cellulose:
Nws yog ua los ntawm paj rwb zoo, kho nrog alkali, thiab reacted nrog ethylene oxide ua tus neeg sawv cev etherification nyob rau hauv lub xub ntiag ntawm isopropanol. Nws qib ntawm kev hloov pauv feem ntau yog 1.5 ~ 2.0. Nws muaj hydrophilicity muaj zog thiab yooj yim rau nqus dej noo.
(1) Hydroxyethyl cellulose yaj tau hauv dej txias, tab sis nws nyuaj rau yaj hauv dej kub. Nws cov tshuaj ruaj khov ntawm qhov kub siab tsis muaj gelling. Nws tuaj yeem siv tau ntev hauv qhov kub siab hauv mortar, tab sis nws cov dej khaws cia qis dua li ntawm methyl cellulose.
(2) Hydroxyethyl cellulose ruaj khov rau cov kua qaub thiab alkali dav dav, thiab alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity me ntsis. Nws cov dispersibility hauv dej yog qhov phem dua li ntawm methyl cellulose thiab hydroxypropyl methyl cellulose.
(3) Hydroxyethyl cellulose muaj kev ua tau zoo tiv thaiv kev qaug zog rau cov mortar, tab sis nws muaj lub sijhawm ntev dua rau cov cement.
(4) Kev ua tau zoo ntawm hydroxyethyl cellulose uas tsim los ntawm qee lub tuam txhab hauv tsev yog qhov qis dua li ntawm methyl cellulose vim nws cov dej ntau thiab cov tshauv ntau.
(5) Cov pwm ntawm cov kua dej ntawm hydroxyethyl cellulose yog qhov hnyav heev. Ntawm qhov kub ntawm kwv yees li 40 ° C, cov pwm yuav tshwm sim hauv 3 txog 5 hnub, uas yuav cuam tshuam rau nws cov kev ua tau zoo.
Carboxymethyl cellulose:
Lonic cellulose ether yog ua los ntawm cov fiber ntuj (paj rwb, thiab lwm yam) tom qab kev kho alkali, siv sodium monochloroacetate ua tus neeg sawv cev etherification, thiab dhau los ntawm ntau yam kev kho mob tshuaj tiv thaiv. Qib ntawm kev hloov pauv feem ntau yog 0.4 ~ 1.4, thiab nws cov kev ua tau zoo cuam tshuam loj heev los ntawm qib ntawm kev hloov pauv.
(1) Carboxymethyl cellulose muaj hygroscopic ntau dua, thiab nws yuav muaj dej ntau dua thaum khaws cia rau hauv qab cov xwm txheej dav dav.
(2) Cov kua dej Carboxymethyl cellulose tsis tsim cov gel, thiab qhov viscosity txo qis nrog qhov nce ntawm qhov kub. Thaum qhov kub tshaj 50 ° C, qhov viscosity tsis rov qab tau.
(3) Nws qhov ruaj khov raug cuam tshuam los ntawm pH. Feem ntau, nws tuaj yeem siv rau hauv gypsum-based mortar, tab sis tsis yog hauv cement-based mortar. Thaum alkaline heev, nws yuav poob viscosity.
(4) Nws cov dej khaws cia qis dua li methyl cellulose. Nws muaj cov nyhuv qeeb rau gypsum-based mortar thiab txo nws lub zog. Txawm li cas los xij, tus nqi ntawm carboxymethyl cellulose qis dua li ntawm methyl cellulose.
Cellulose Alkyl Ether:
Cov sawv cev yog methyl cellulose thiab ethyl cellulose. Hauv kev tsim khoom lag luam, methyl chloride lossis ethyl chloride feem ntau yog siv los ua tus neeg sawv cev etherification, thiab cov tshuaj tiv thaiv yog raws li nram no:
Hauv cov mis, R sawv cev rau CH3 lossis C2H5. Alkali concentration tsis yog tsuas yog cuam tshuam rau qib ntawm etherification, tab sis kuj cuam tshuam rau kev siv alkyl halides. Qhov qis dua qhov alkali concentration, qhov muaj zog dua hydrolysis ntawm alkyl halide. Yuav kom txo tau kev siv etherifying tus neeg sawv cev, qhov alkali concentration yuav tsum tau nce. Txawm li cas los xij, thaum qhov alkali concentration siab dhau, qhov o ntawm cellulose raug txo, uas tsis zoo rau qhov etherification reaction, thiab yog li ntawd qhov degree ntawm etherification raug txo. Rau lub hom phiaj no, concentrated lye lossis solid lye tuaj yeem ntxiv thaum lub sijhawm reaction. Lub reactor yuav tsum muaj lub cuab yeej zoo stirring thiab tearing kom cov alkali tuaj yeem faib sib npaug. Methyl cellulose siv dav ua cov khoom ua kom tuab, nplaum thiab tiv thaiv colloid thiab lwm yam. Nws kuj tseem siv tau ua cov khoom tawg rau emulsion polymerization, cov khoom tawg rau cov noob, cov khoom siv textile slurry, cov khoom ntxiv rau zaub mov thiab tshuaj pleev ib ce, cov khoom nplaum kho mob, cov khoom siv txheej tshuaj, thiab siv rau hauv cov xim latex, cov kua luam ntawv, kev tsim cov khoom siv ceramic, thiab sib xyaw rau hauv cement Siv los tswj lub sijhawm teeb tsa thiab ua kom lub zog pib nce ntxiv, thiab lwm yam. Cov khoom lag luam ethyl cellulose muaj lub zog kho tshuab siab, yooj ywm, tiv taus kub thiab tiv taus txias. Cov ethyl cellulose uas tsis muaj kev hloov pauv qis yog yaj hauv dej thiab cov kua alkaline dilute, thiab cov khoom lag luam uas muaj kev hloov pauv siab yog yaj hauv feem ntau cov kuab tshuaj organic. Nws muaj kev sib raug zoo nrog ntau yam resins thiab plasticizers. Nws tuaj yeem siv los ua cov yas, zaj duab xis, cov kua roj vanish, cov nplaum, cov roj hmab thiab cov ntaub ntawv txheej rau cov tshuaj, thiab lwm yam. Kev qhia txog cov pab pawg hydroxyalkyl rau hauv cellulose alkyl ethers tuaj yeem txhim kho nws cov solubility, txo nws qhov rhiab heev rau salting tawm, nce qhov kub gelation thiab txhim kho cov khoom kub yaj, thiab lwm yam. Qhov kev hloov pauv ntawm cov khoom saum toj no sib txawv nrog qhov xwm txheej ntawm cov substituents thiab qhov piv ntawm alkyl rau hydroxyalkyl pab pawg.
Cellulose Hydroxyalkyl Ether:
Cov sawv cev yog hydroxyethyl cellulose thiab hydroxypropyl cellulose. Cov neeg sawv cev etherifying yog epoxides xws li ethylene oxide thiab propylene oxide. Siv acid lossis base ua catalyst. Kev tsim khoom lag luam yog los cuam tshuam alkali cellulose nrog tus neeg sawv cev etherification:hydroxyethyl cellulosenrog tus nqi hloov pauv siab yog soluble hauv dej txias thiab dej kub. Hydroxypropyl cellulose nrog tus nqi hloov pauv siab tsuas yog soluble hauv dej txias tab sis tsis nyob hauv dej kub. Hydroxyethyl cellulose tuaj yeem siv ua cov khoom siv tuab rau cov txheej latex, cov ntawv luam ntawv thiab cov xim pleev xim, cov ntaub ntawv ntsuas ntawv, cov nplaum thiab cov colloids tiv thaiv. Kev siv hydroxypropyl cellulose zoo ib yam li hydroxyethyl cellulose. Hydroxypropyl cellulose nrog tus nqi hloov pauv qis tuaj yeem siv ua cov tshuaj ntxiv, uas tuaj yeem muaj ob qho tib si khi thiab tawg.
Carboxymethyl cellulose, lub npe luv lus Askiv CMC, feem ntau muaj nyob rau hauv daim ntawv ntawm sodium ntsev. Tus neeg sawv cev etherifying yog monochloroacetic acid, thiab cov tshuaj tiv thaiv yog raws li nram no:
Carboxymethyl cellulose yog cov cellulose ether uas yaj tau hauv dej uas siv ntau tshaj plaws. Yav dhau los, nws feem ntau yog siv ua av nkos, tab sis tam sim no nws tau nthuav dav los siv ua cov khoom ntxiv rau cov tshuaj ntxuav khaub ncaws, cov tshuaj pleev xim latex, txheej rau cov ntawv thiab ntawv, thiab lwm yam. Carboxymethyl cellulose ntshiab siv tau rau hauv cov khoom noj, tshuaj, tshuaj pleev ib ce, thiab kuj yog cov nplaum rau cov khoom siv av nplaum thiab pwm.
Polyanionic cellulose (PAC) yog ib qho ionic cellulose ether thiab yog ib yam khoom siv hloov carboxymethyl cellulose (CMC). Nws yog ib hom hmoov lossis granule dawb, dawb tawm lossis daj me ntsis, tsis muaj tshuaj lom, tsis muaj saj, yooj yim yaj hauv dej los ua ib qho kua pob tshab nrog qee qhov viscosity, muaj kev ruaj khov zoo dua rau kev tiv thaiv kub thiab ntsev, thiab muaj zog tua kab mob. Tsis muaj pwm thiab lwj. Nws muaj cov yam ntxwv ntawm kev ntshiab siab, qib siab ntawm kev hloov pauv, thiab kev faib tawm ntawm cov khoom hloov pauv sib xws. Nws tuaj yeem siv ua binder, thickener, rheology modifier, fluid poob reducer, suspension stabilizer, thiab lwm yam. Polyanionic cellulose (PAC) yog siv dav hauv txhua qhov kev lag luam uas CMC tuaj yeem siv, uas tuaj yeem txo qhov ntau npaum li cas, yooj yim siv, muab kev ruaj khov zoo dua thiab ua tau raws li cov txheej txheem siab dua.
Cyanoethyl cellulose yog cov khoom tshuaj tiv thaiv ntawm cellulose thiab acrylonitrile nyob rau hauv lub catalysis ntawm alkali.
Cyanoethyl cellulose muaj qhov dielectric constant siab thiab coefficient poob qis thiab siv tau ua cov resin matrix rau phosphor thiab electroluminescent teeb. cyanoethyl cellulose uas tsis tshua muaj neeg hloov pauv siv tau ua daim ntawv rwb thaiv tsev rau transformers.
Cov roj cawv ethers siab dua, alkenyl ethers, thiab aromatic alcohol ethers ntawm cellulose tau raug npaj, tab sis tsis tau siv rau hauv kev xyaum.
Cov txheej txheem npaj ntawm cellulose ether tuaj yeem muab faib ua dej nruab nrab txoj kev, cov kuab tshuaj, cov txheej txheem kneading, slurry txoj kev, roj-khoom, kua theem txoj kev thiab kev sib xyaw ua ke ntawm cov txheej txheem saum toj no.
5. Txoj cai npaj:
Cov kua qaub α-cellulose siab tau muab ntub nrog cov kua alkaline kom nws o thiab rhuav tshem cov hydrogen bonds ntau dua, pab txhawb kev sib kis ntawm cov tshuaj reagents thiab tsim cov alkali cellulose, thiab tom qab ntawd teb nrog tus neeg sawv cev etherification kom tau txais cellulose ether. Cov neeg sawv cev etherifying suav nrog hydrocarbon halides (lossis sulfates), epoxides, thiab α thiab β unsaturated compounds nrog electron acceptors.
6. Kev ua tau zoo yooj yim:
Cov tshuaj ntxiv ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua tau zoo ntawm kev tsim cov tshuaj mortar qhuav, thiab suav txog ntau dua 40% ntawm cov nqi khoom siv hauv cov tshuaj mortar qhuav. Ib feem loj ntawm cov tshuaj ntxiv hauv kev lag luam hauv tsev yog muab los ntawm cov tuam txhab txawv teb chaws, thiab cov koob tshuaj siv rau cov khoom kuj yog muab los ntawm tus neeg muag khoom. Yog li ntawd, tus nqi ntawm cov khoom siv mortar qhuav tseem siab, thiab nws nyuaj rau kev ua kom nrov npe ntawm cov tshuaj masonry thiab plastering nrog ntau thiab ntau yam. Cov khoom lag luam siab kawg raug tswj hwm los ntawm cov tuam txhab txawv teb chaws, thiab cov chaw tsim khoom siv mortar qhuav muaj cov txiaj ntsig qis thiab tus nqi tsis zoo; kev siv cov tshuaj ntxiv tsis muaj kev tshawb fawb thiab tsom mus rau, thiab ua raws li cov qauv txawv teb chaws.
Tus neeg sawv cev khaws dej yog ib qho tseem ceeb admixture los txhim kho kev ua tau zoo ntawm cov mortar qhuav sib xyaw, thiab nws kuj yog ib qho ntawm cov admixtures tseem ceeb los txiav txim siab tus nqi ntawm cov khoom siv mortar qhuav sib xyaw. Lub luag haujlwm tseem ceeb ntawm cellulose ether yog khaws dej.
Cellulose ether yog ib lo lus dav dav rau cov khoom tsim los ntawm cov tshuaj tiv thaiv ntawm alkali cellulose thiab etherifying agent nyob rau hauv qee qhov xwm txheej. Alkali cellulose raug hloov los ntawm cov neeg sawv cev etherifying sib txawv kom tau txais cov cellulose ethers sib txawv. Raws li cov khoom ionization ntawm cov substituents, cellulose ethers tuaj yeem muab faib ua ob pawg: ionic (xws li carboxymethyl cellulose) thiab nonionic (xws li methyl cellulose). Raws li hom substituent, cellulose ether tuaj yeem muab faib ua monoether (xws li methyl cellulose) thiab sib xyaw ether (xws li hydroxypropyl methyl cellulose). Raws li kev yaj sib txawv, nws tuaj yeem muab faib ua dej yaj (xws li hydroxyethyl cellulose) thiab cov organic solvent solubility (xws li ethyl cellulose). Cov mortar qhuav sib xyaw feem ntau yog cellulose yaj hauv dej, thiab dej yaj cellulose yog muab faib ua hom tam sim ntawd thiab hom kev yaj qeeb-kho nto.
Lub mechanism ntawm kev ua haujlwm ntawm cellulose ether hauv mortar yog raws li nram no:
(1) Tom qab lubcellulose etherHauv cov mortar yog yaj rau hauv dej, qhov kev faib tawm zoo thiab sib xws ntawm cov khoom siv cementitious hauv lub kaw lus tau ua kom ntseeg tau vim yog qhov kev ua haujlwm ntawm qhov chaw, thiab cellulose ether, ua ib qho colloid tiv thaiv, "qhwv" cov khoom khov thiab Ib txheej ntawm cov zaj duab xis lubricating yog tsim rau ntawm nws qhov chaw sab nraud, uas ua rau lub kaw lus mortar ruaj khov dua, thiab tseem txhim kho qhov fluidity ntawm mortar thaum lub sijhawm sib tov thiab qhov du ntawm kev tsim kho.
(2) Vim nws cov qauv molecular, cov kua cellulose ether ua rau cov dej noo hauv cov mortar tsis yooj yim poob, thiab maj mam tso nws tawm mus ntev, ua rau cov mortar khaws dej zoo thiab ua haujlwm tau zoo.
Lub sijhawm tshaj tawm: Plaub Hlis-28-2024