Yuav ua li cas kom Cellulose ether?

Cellulose ether yog ib hom cellulose derivative tau los ntawm etherification hloov ntawm cellulose. Nws yog dav siv vim nws zoo heev thickening, emulsification, ncua kev kawm ntawv, tsim zaj duab xis, tiv thaiv colloid, noo noo retention, thiab adhesion zog. Nws ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev lag luam hauv lub tebchaws hauv kev tshawb fawb thiab kev lag luam xws li zaub mov, tshuaj, papermaking, coatings, cov ntaub ntawv hauv tsev, roj rov qab, textiles thiab cov khoom siv hluav taws xob. Hauv daim ntawv no, kev tshawb fawb txog kev hloov pauv etherification ntawm cellulose raug tshuaj xyuas.

Celluloseetheryog cov organic polymer ntau tshaj plaws hauv qhov xwm txheej. Nws yog tauj dua tshiab, ntsuab thiab biocompatible. Nws yog ib qho tseem ceeb raw khoom rau chemical engineering. Raws li cov khoom sib txawv ntawm cov molecule tau los ntawm cov tshuaj tiv thaiv etherification, nws tuaj yeem muab faib ua ib qho ethers thiab sib xyaw. cellulose ethers.Ntawm no peb tshuaj xyuas cov kev tshawb fawb tau ua tiav ntawm kev sib txuas ntawm ib leeg ethers, suav nrog alkyl ethers, hydroxyalkyl ethers, carboxyalkyl ethers, thiab sib xyaw ethers.

Cov lus tseem ceeb: cellulose ether, etherification, ib leeg ether, sib xyaw ether, kev tshawb fawb kev vam meej

1.Etherification cov tshuaj tiv thaiv cellulose

Cov tshuaj tiv thaiv etherification ntawm cellulose ether yog qhov tseem ceeb tshaj plaws cellulose derivatization cov tshuaj tiv thaiv.Etherification ntawm cellulose yog ib tug series ntawm derivatives tsim los ntawm cov tshuaj tiv thaiv ntawm hydroxyl pawg ntawm cellulose molecular chains nrog alkylating agents nyob rau hauv alkaline tej yam kev mob. Muaj ntau hom cellulose ether cov khoom, uas tuaj yeem muab faib ua ib leeg ethers thiab sib xyaw ethers raws li cov khoom sib txawv ntawm cov molecules tau los ntawm cov tshuaj tiv thaiv etherification. Ib leeg ethers tuaj yeem muab faib ua alkyl ethers, hydroxyalkyl ethers thiab carboxyalkyl ethers, thiab sib xyaw ethers xa mus rau ethers nrog ob lossis ntau pawg txuas nrog hauv cov qauv molecular. Ntawm cov khoom lag luam cellulose ether, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) yog sawv cev, ntawm qee cov khoom lag luam.

2.Synthesis ntawm cellulose ether

2.1 Synthesis ntawm ib ether

Ib leeg ethers muaj xws li alkyl ethers (xws li ethyl cellulose, propyl cellulose, phenyl cellulose, cyanoethyl cellulose, thiab lwm yam), hydroxyalkyl ethers (xws li hydroxymethyl cellulose, hydroxyethyl cellulose, thiab lwm yam), carboxyalkyl ethers (xws li carboxoseymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose, thiab lwm yam. lwm yam).

2.1.1 Synthesis ntawm alkyl ethers

Berglund thiab thawj zaug kho cellulose nrog NaOH tov ntxiv nrog ethyl chloride, ces ntxiv methyl chloride ntawm qhov kub ntawm 65.°C rau 90°C thiab lub siab ntawm 3bar rau 15bar, thiab reacted los tsim methyl cellulose ether. Txoj kev no tuaj yeem ua haujlwm tau zoo Kom tau txais cov dej-soluble methyl cellulose ethers nrog ntau qib kev hloov pauv.

Ethylcellulose yog dawb thermoplastic granule los yog hmoov. Cov khoom lag luam dav dav muaj 44% ~ 49% ethoxy. Soluble nyob rau hauv feem ntau cov organic solvents, insoluble nyob rau hauv dej. lub pulp lossis paj rwb linters nrog 40% ~ 50% sodium hydroxide aqueous tov, thiab alkalized cellulose yog ethoxylated nrog ethyl chloride los tsim ethyl cellulose. ua tiav kev sib txuas ntawm ethyl cellulose (EC) nrog cov ntsiab lus ethoxy ntawm 43.98% los ntawm ib txoj hauv kev los ntawm kev ua haujlwm cellulose nrog ntau tshaj ethyl chloride thiab sodium hydroxide, siv toluene ua ib qho diluent. Toluene tau siv los ua cov diluent hauv kev sim. Thaum lub sij hawm etherification cov tshuaj tiv thaiv, nws tuaj yeem tsis tsuas yog txhawb kev nthuav tawm ntawm ethyl chloride mus rau alkali cellulose, tab sis kuj yaj cov ethyl cellulose hloov tau. Thaum lub sij hawm cov tshuaj tiv thaiv, qhov unreacted ib feem yuav tsis tu ncua nthuav tawm, ua tus neeg sawv cev etherification Nws yog ib qho yooj yim mus txeeb, kom cov tshuaj tiv thaiv ethylation hloov los ntawm heterogeneous mus rau homogeneous, thiab kev faib ntawm substituents nyob rau hauv cov khoom yog ntau uniform.

siv ethyl bromide ua etherification tus neeg sawv cev thiab tetrahydrofuran li diluent rau synthesize ethyl cellulose (EC), thiab characterized cov khoom qauv los ntawm infrared spectroscopy, nuclear magnetic resonance thiab gel permeation chromatography. Nws yog xam tias qhov degree ntawm kev hloov ntawm cov synthesized ethyl cellulose yog hais txog 2.5, lub molecular loj faib yog nqaim, thiab nws muaj zoo solubility nyob rau hauv cov organic solvents.

cyanoethyl cellulose (CEC) los ntawm homogeneous thiab heterogeneous txoj kev siv cellulose nrog ntau qib ntawm polymerization raws li raw cov ntaub ntawv, thiab npaj ntom CEC membrane cov ntaub ntawv los ntawm kev daws casting thiab kub nias. Porous CEC daim nyias nyias tau npaj los ntawm cov txheej txheem hnyav-induced theem sib cais (NIPS) thev naus laus zis, thiab barium titanate / cyanoethyl cellulose (BT / CEC) nanocomposite membrane cov ntaub ntawv tau npaj los ntawm NIPS thev naus laus zis, thiab lawv cov qauv thiab cov khoom tau kawm.

siv tus kheej tsim cellulose hnyav (alkali / urea tov) raws li cov tshuaj tiv thaiv nruab nrab rau homogeneously synthesize cyanoethyl cellulose (CEC) nrog acrylonitrile ua tus neeg sawv cev etherification, thiab tau tshawb fawb txog cov qauv, cov khoom thiab kev siv ntawm cov khoom. kawm tob. Thiab los ntawm kev tswj hwm cov xwm txheej sib txawv, CECs nrog DS qhov tseem ceeb ntawm 0.26 txog 1.81 tuaj yeem tau txais.

2.1.2 Synthesis ntawm hydroxyalkyl ethers

Ntxuam Junlin thiab al npaj hydroxyethyl cellulose (HEC) nyob rau hauv 500 L reactor siv cov paj rwb refined li raw khoom thiab 87.7% isopropanol-dej ua hnyav los ntawm ib-kauj ruam alkalization, step-by-step neutralization thiab step-by-step etherification. . Cov txiaj ntsig tau pom tias cov khoom npaj hydroxyethyl cellulose (HEC) tau hloov cov molar MS ntawm 2.2-2.9, ncav cuag tus qauv zoo ib yam li cov khoom lag luam qib Dows 250 HEC nrog kev hloov molar ntawm 2.2-2.4. Kev siv HEC hauv kev tsim cov xim latex tuaj yeem txhim kho cov yeeb yaj kiab tsim thiab qib ntawm cov xim latex.

Liu Dan thiab lwm tus tau tham txog kev npaj quaternary ammonium ntsev cationic hydroxyethyl cellulose los ntawm ib nrab qhuav txoj kev ntawm hydroxyethyl cellulose (HEC) thiab 2,3-epoxypropyltrimethylammonium chloride (GTA) nyob rau hauv qhov kev txiav txim ntawm alkali catalysis. ether tej yam kev mob. Cov nyhuv ntawm kev ntxiv cationic hydroxyethyl cellulose ether ntawm daim ntawv tau tshawb xyuas. Cov txiaj ntsig kev sim qhia tau hais tias: nyob rau hauv bleached hardwood pulp, thaum hloov cov degree ntawm cationic hydroxyethyl cellulose ether yog 0.26, tag nrho cov tuav tus nqi nce 9%, thiab cov dej pom tus nqi nce 14%; Nyob rau hauv bleached hardwood pulp, thaum Thaum tus nqi ntawm cationic hydroxyethyl cellulose ether yog 0.08% ntawm cov pulp fiber, nws muaj ib tug tseem ceeb txhawb zog nyhuv ntawm daim ntawv; Qhov ntau dua qhov kev hloov pauv ntawm cationic cellulose ether, qhov ntau dua qhov cationic charge ceev, thiab qhov zoo dua qhov kev txhawb zog.

Zhanhong siv cov txheej txheem ua kua-theem synthesis los npaj hydroxyethyl cellulose nrog tus nqi viscosity ntawm 5×104 mPa·s lossis ntau dua thiab cov hmoov tshauv tsawg dua 0.3% los ntawm ob-kauj ruam txheej txheem ntawm alkalization thiab etherification. Ob txoj kev alkalization tau siv. Thawj txoj kev yog siv acetone ua ib qho diluent. Cov khoom siv cellulose yog ncaj qha nyob rau hauv ib qho concentration ntawm sodium hydroxide aqueous kua. Tom qab cov tshuaj tiv thaiv basification tau ua tiav, tus neeg sawv cev etherification tau ntxiv los ua ncaj qha rau cov tshuaj tiv thaiv etherification. Qhov thib ob txoj kev yog tias cov khoom siv cellulose yog alkalized nyob rau hauv ib qho aqueous tov ntawm sodium hydroxide thiab urea, thiab alkali cellulose npaj los ntawm txoj kev no yuav tsum tau nyem kom tshem tawm ntau tshaj lye ua ntej cov tshuaj tiv thaiv etherification. Cov txiaj ntsig kev sim qhia tau hais tias cov yam ntxwv xws li xaiv cov tshuaj diluent, tus nqi ntawm ethylene oxide ntxiv, lub sij hawm alkalization, qhov kub thiab lub sij hawm ntawm thawj cov tshuaj tiv thaiv, thiab qhov kub thiab lub sij hawm ntawm qhov thib ob cov tshuaj tiv thaiv tag nrho muaj kev cuam tshuam zoo rau kev ua haujlwm. ntawm cov khoom.

Xu Qin et al. nqa tawm etherification cov tshuaj tiv thaiv ntawm alkali cellulose thiab propylene oxide, thiab synthesized hydroxypropyl cellulose (HPC) nrog tsawg hloov degree los ntawm cov roj-khoom siv theem. Cov teebmeem ntawm pawg loj ntawm propylene oxide, nyem piv thiab etherification kub ntawm qib etherification ntawm HPC thiab kev siv tau zoo ntawm propylene oxide tau kawm. Cov txiaj ntsig tau pom tias qhov kev ua kom zoo tshaj plaws ntawm HPC yog propylene oxide pawg feem 20% (qhov loj piv rau cellulose), alkali cellulose extrusion ratio 3.0, thiab etherification kub 60°C. Cov qauv kuaj HPC los ntawm nuclear magnetic resonance qhia tau hais tias qib ntawm etherification ntawm HPC yog 0.23, qhov kev siv tau zoo ntawm propylene oxide yog 41.51%, thiab cellulose molecular saw txuas nrog hydroxypropyl pawg.

Kong Xingjie et al. npaj hydroxypropyl cellulose nrog ionic kua ua ib qho hnyav kom paub txog homogeneous cov tshuaj tiv thaiv cellulose thiaj li paub txog cov kev cai ntawm cov tshuaj tiv thaiv txheej txheem thiab cov khoom. Thaum lub sij hawm sim, cov hluavtaws imidazole phosphate ionic kua 1, 3-diethylimidazole diethyl phosphate yog siv los yaj microcrystalline cellulose, thiab hydroxypropyl cellulose tau txais los ntawm alkalization, etherification, acidification, thiab ntxuav.

2.1.3 Synthesis ntawm carboxyalkyl ethers

Carboxymethyl cellulose feem ntau yog carboxymethyl cellulose (CMC). Cov tshuaj aqueous ntawm carboxymethyl cellulose muaj cov dej num ntawm thickening, film forming, bonding, dej tuav, colloid tiv thaiv, emulsification thiab ncua kev kawm ntawv, thiab yog dav siv nyob rau hauv ntxuav. Pharmaceuticals, zaub mov, tshuaj txhuam hniav, textiles, printing thiab dyeing, papermaking, roj av, mining, tshuaj, ceramics, electronics Cheebtsam, roj hmab, xim, tshuaj tua kab, tshuaj pleev ib ce, tawv, plastics thiab roj drilling, thiab lwm yam.

Xyoo 1918, German E. Jansen tau tsim txoj kev sib txuas ntawm carboxymethyl cellulose. Xyoo 1940, Kalle Hoobkas ntawm German IG Farbeninaustrie Company paub txog kev tsim khoom. Xyoo 1947, Wyandotle Chemical Company ntawm Tebchaws Meskas tau ua tiav cov txheej txheem ntau lawm. kuv lub teb chaws thawj zaug muab tso rau hauv CMC industrial ntau lawm nyob rau hauv Shanghai Celluloid Hoobkas nyob rau hauv 1958. Carboxymethyl cellulose yog ib tug cellulose ether ua los ntawm refined paj rwb nyob rau hauv qhov kev txiav txim ntawm sodium hydroxide thiab chloroacetic acid. Nws txoj kev tsim khoom lag luam tuaj yeem muab faib ua ob pawg: dej-raws li txoj kev thiab cov kuab tshuaj raws li kev sib txawv etherification media. Cov txheej txheem siv dej raws li qhov nruab nrab cov tshuaj tiv thaiv yog hu ua dej nruab nrab txoj kev, thiab cov txheej txheem uas muaj cov organic hnyav hauv cov tshuaj tiv thaiv nruab nrab yog hu ua cov txheej txheem hnyav.

Nrog rau kev tshawb fawb tob tob thiab kev nce qib ntawm cov thev naus laus zis, cov tshuaj tiv thaiv tshiab tau siv rau kev sib txuas ntawm carboxymethyl cellulose, thiab cov kuab tshuaj tshiab muaj qhov cuam tshuam loj rau cov txheej txheem tshuaj tiv thaiv lossis cov khoom zoo. Olaru et al. pom tias cov tshuaj tiv thaiv carboxymethylation ntawm cellulose siv ethanol-acetone sib xyaw ua ke zoo dua li ntawm ethanol lossis acetone ib leeg. Nicholson et al. Hauv qhov system, CMC nrog qib qis ntawm kev hloov pauv tau npaj. Philipp thiab al npaj siab hloov CMC nrog N-methylmorpholine-N oxide thiab N, N dimethylacetamide / lithium chloride hnyav tshuab feem. Cai et al. tsim ib txoj hauv kev npaj CMC hauv NaOH / urea hnyav system. Ramos et al. siv DMSO / tetrabutylammonium fluoride ionic kua system ua cov kuab tshuaj rau carboxymethylate cov cellulose raw khoom refined los ntawm paj rwb thiab sisal, thiab tau txais ib tug CMC cov khoom nrog ib tug hloov qib siab li 2.17. Chen Jinghuan et al. siv cellulose nrog siab siab siab (20%) raws li raw khoom, sodium hydroxide thiab acrylamide raws li kev hloov kho reagents, nqa tawm carboxyethylation hloov kho cov tshuaj tiv thaiv ntawm lub sij hawm thiab kub, thiab thaum kawg tau carboxyethyl puag cellulose. Cov ntsiab lus carboxyethyl ntawm cov khoom hloov kho tuaj yeem tswj tau los ntawm kev hloov pauv ntawm sodium hydroxide thiab acrylamide.

2.2 Synthesis ntawm mixed ethers

Hydroxypropyl methyl cellulose ether yog ib hom non-polar cellulose ether soluble hauv dej txias tau los ntawm ntuj cellulose los ntawm alkalization thiab etherification hloov. Nws yog alkalized nrog sodium hydroxide tov thiab ntxiv ib qho nyiaj ntawm Isopropanol thiab toluene hnyav, tus neeg sawv cev etherification uas tau txais yog methyl chloride thiab propylene oxide.

Dai Mingyun et al. siv hydroxyethyl cellulose (HEC) ua cov pob txha ntawm hydrophilic polymer, thiab grafted tus neeg sawv cev hydrophobizing butyl glycidyl ether (BGE) mus rau lub caj qaum los ntawm etherification cov tshuaj tiv thaiv los kho cov hydrophobic pawg butyl pawg. Lub degree ntawm kev hloov ntawm pab pawg, kom nws muaj ib tug haum hydrophilic-lipophilic tshuav nqi, thiab ib tug kub-responsive 2-hydroxy-3-butoxypropyl hydroxyethyl cellulose (HBPEC) yog npaj; cov cuab yeej ntsuas kub yog npaj Cov khoom siv ua haujlwm ntawm cellulose muab ib txoj hauv kev tshiab rau kev siv cov khoom siv ua haujlwm hauv thaj chaw ntawm cov tshuaj tiv thaiv kev tso tawm thiab biology.

Chen Yangming thiab lwm tus siv hydroxyethyl cellulose ua cov khoom siv raw, thiab hauv isopropanol tov system, ntxiv me me ntawm Na2B4O7 rau cov reactant rau homogeneous cov tshuaj tiv thaiv los npaj tov ether hydroxyethyl carboxymethyl cellulose. Cov khoom yog instantly nyob rau hauv dej, thiab viscosity yog ruaj khov.

Wang Peng siv natural cellulose refined paj rwb raws li cov khoom siv raw, thiab siv cov txheej txheem etherification ib-kauj ruam los tsim carboxymethyl hydroxypropyl cellulose nrog cov tshuaj tiv thaiv zoo, siab viscosity, zoo acid tsis kam thiab ntsev tiv thaiv los ntawm alkalization thiab etherification cov tshuaj tiv thaiv Compound ether. Siv cov txheej txheem etherification ib-kauj ruam, cov khoom tsim carboxymethyl hydroxypropyl cellulose muaj ntsev zoo, acid tsis kam thiab solubility. Los ntawm kev hloov cov txheeb ze ntawm propylene oxide thiab chloroacetic acid, cov khoom uas muaj carboxymethyl thiab hydroxypropyl sib txawv tuaj yeem npaj tau. Cov txiaj ntsig kev sim qhia tau hais tias cov carboxymethyl hydroxypropyl cellulose uas tsim los ntawm ib-kauj ruam txoj kev muaj lub voj voog luv luv, kev siv cov kuab tshuaj tsawg, thiab cov khoom muaj kev tiv thaiv zoo rau monovalent thiab divalent ntsev thiab cov kua qaub zoo. Piv nrog rau lwm cov khoom lag luam cellulose ether, nws muaj kev sib tw muaj zog hauv kev tshawb nrhiav zaub mov thiab roj.

Hydroxypropylmethylcellulose (HPMC) yog cov khoom siv ntau yam thiab ua tau zoo tshaj plaws ntawm txhua hom cellulose, thiab nws kuj yog ib tus neeg sawv cev ntawm kev lag luam ntawm cov ethers sib xyaw. Xyoo 1927, hydroxypropylmethylcellulose (HPMC) tau ua tiav zoo thiab cais tawm. Xyoo 1938, Dow Chemical Co. ntawm Tebchaws Meskas tau paub txog kev tsim khoom ntawm methyl cellulose thiab tsim cov cim lag luam zoo "Methocel". Kev lag luam loj loj ntawm hydroxypropyl methylcellulose tau pib hauv Tebchaws Meskas hauv xyoo 1948. Cov txheej txheem tsim khoom ntawm HPMC tuaj yeem muab faib ua ob pawg: cov txheej txheem roj theem thiab cov txheej txheem ua kua theem. Tam sim no, cov teb chaws tsim kho xws li Europe, Amelikas thiab Nyij Pooj tau siv cov txheej txheem roj ntau dua, thiab kev tsim tawm hauv tsev ntawm HPMC feem ntau yog raws li cov txheej txheem ua kua theem.

Zhang Shuangjian thiab lwm tus ua kom zoo nkauj paj rwb hmoov ua raw khoom, alkalized nws nrog sodium hydroxide nyob rau hauv cov tshuaj tiv thaiv hnyav nruab nrab toluene thiab isopropanol, etherified nws nrog etherifying tus neeg saib xyuas propylene oxide thiab methyl chloride, reacted thiab npaj ib hom instant hydroxypropyl methyl cawv puag cellulose ether.

3. Outlook

Cellulose yog ib qho tseem ceeb ntawm cov khoom siv tshuaj lom neeg thiab tshuaj lom neeg uas muaj kev nplua nuj nyob hauv cov peev txheej, ntsuab thiab ib puag ncig tus phooj ywg, thiab rov ua dua tshiab. Cov derivatives ntawm cellulose etherification hloov kho muaj kev ua tau zoo, ntau yam kev siv thiab kev siv zoo heev, thiab ua tau raws li cov kev xav tau ntawm lub teb chaws kev lag luam mus rau qhov loj. Thiab cov kev xav tau ntawm kev txhim kho kev sib raug zoo, nrog rau kev ua tiav thev naus laus zis tsis tu ncua thiab kev ua lag luam kev lag luam yav tom ntej, yog tias cov khoom siv hluavtaws thiab cov txheej txheem hluavtaws ntawm cellulose derivatives tuaj yeem ua haujlwm ntau dua, lawv yuav siv tau ntau dua thiab paub txog ntau yam kev siv. Tus nqi.