Cov qauv qauv ntawm obNeeg muaj neeg ua haujlwmtau muab nyob rau hauv cov duab 1.1 thiab 1.2. Txhua β-d-dehydrated grape ntawm lub cellulose molecule
Cov dej qab zib (chav ntsuas ntawm cellulose) raug hloov nrog ib pawg EETE rau ntawm C (2) thiab C (6) txoj haujlwm, piv txwv li ntawm peb
ib pawg ether. Vim tias muaj cov pab pawg hydroxyl, cellulose macromolecules muaj intramolecular muaj intramolecular thiab cov kev sib txuam hydrogen bonds, uas nyuaj rau yaj hauv dej.
Thiab nws nyuaj rau yaj nyob rau yuav luag txhua cov kuab organic. Txawm li cas los xij, tom qab qhib ntawm cov cellulose, cov pab pawg ether tau qhia rau hauv cov kab hlau,
Nyob rau hauv txoj kev no, hydrogen bonds nyob rau hauv thiab ntawm molecules ntawm cellules ntawm cellule muaj kev puas tsuaj, thiab nws cov solubility tuaj yeem txhim kho.
zoo heev txhim kho. Ntawm lawv, Daim duab 1.1 yog cov qauv dav dav ntawm ob lub anhydoglulucose ntawm cellulogose ether molecular saw, R1-R6 = h
lossis organic hloov chaw. 1.2 yog ib qho tawg ntawm carboxymethyl hydrokyethyl cellulose molecular molecular, cov qib ntawm hloov carboxymethyl yog 0.5,4
Qhov kev hloov kho ntawm hydroxyethyl yog 2.0, thiab cov nyiaj hniav mob ntshav hloov pauv yog 3.0.
Rau txhua tus hloov ntawm cellulose, tag nrho cov nyiaj ntawm nws etherification tuaj yeem qhia raws li qib degrements (DS). ua los ntawm cov fibers
Nws tuaj yeem pom los ntawm cov qauv ntawm prime molecule uas cov degree ntawm chaw hloov chaw ntawm 0-3. Ntawd yog, txhua lub tsev muaj anhydoglucose hauv lub nplhaib ntawm cellulose
, tus naj npawb nruab nrab ntawm cov pab pawg hydroxyl hloov los ntawm kev ncua cov pab pawg ntawm lub hnub ci tus neeg sawv cev. Vim yog cov pab pawg hydroxyls ntawm cellulose, nws qhov kev hloov pauv
Lub hereherification yuav tsum tau rov pib dua los ntawm cov pab pawg hydroxyl tshiab. Yog li ntawd, qib degree ntawm kev hloov pauv ntawm hom ntawm cov cellulose ether tuaj yeem qhia hauv moles.
degree ntawm hloov chaw (MS). Qhov no hu ua molar deglas ntawm kev hloov pauv cov nyiaj ntawm tus neeg sawv cev ntawm lub cev tus neeg sawv cev ntxiv rau txhua ntu ntawm cov cellulogose
Qhov nruab nrab loj ntawm cov reactants.
1 cov qauv dav dav ntawm chav dej qab zib
2 tawg ntawm cellulose aught molecular chains
1.2.2 Kev Qhia Txog Cellulose ntawm cov neeg muaj cai
Txawm hais tias cellulose kev ua yog ib tug neeg raug kev tsim txom lossis kev sib xyaw ua ke, lawv cov khoom siv tau sib txawv me ntsis. Cellulose Macromolecules
Yog hais tias pawg hydroxyl ntawm chav tsev nyob hloov los ntawm cov pab pawg hydrophilic, cov khoom lag luam tuaj yeem muaj qis dua kev hloov pauv hauv qhov xwm txheej qis dua.
Nws muaj qee qhov dej solubility; Yog tias nws tau hloov los ntawm pab pawg hydropobic, cov khoom muaj qee qib ntawm kev hloov pauv tsuas yog thaum cov degrerate.
Dej-soluble, tsis tshua muaj zog cellulose etherification cov khoom yuav tsuas yog sw sw dej, lossis yaj nyob rau hauv cov kev daws teeb meem alkali
nruab nrab.
Raws li cov hom hloov chaw, cov kws ua haujlwm cellulose tuaj yeem faib ua peb pawg: alkyl pawg, xws li methyl cellulose, Ethylorm;
Hydroxyalkyls, xws li hydroxyethyl cellulose, hydroxyprropyl cellulose; lwm tus, xws li Carboxymethyl cellulose, thiab lwm yam yog tias ionization
Kev ua raws li, cov neeg tswj hwm cellulose tuaj yeem muab faib ua: ionic, xws li cov cloboxymethyl cellulose; tsis-ionic, xws li hydroxyethyl cellulose; mixed
Ntaus, xws li hydroxyethyl Carboxymethyl cellulose. Raws li kev faib tawm ntawm solubility, cellulose tuaj yeem faib ua: dej-soluble, xws li Carboxymethyl cellulose,
Hydroxyethyl cellulose; dej-insoluble, xws li methyl cellulose, thiab lwm yam.
1.2.3 Cov Khoom Siv thiab Kev Siv Ntawm Cellulose Muaj Cov Neeg Muaj
Cellulose ether yog hom khoom tom qab cellulose hloov kho, thiab cellulose ether muaj ntau yam khoom muaj ntau yam khoom muaj nqis. nyiam
Nws muaj cov yeeb yaj kiab zoo-tsim cov khoom; Ua cov luam tawm luam ntawv, nws muaj cov dej ua kom zoo, thickening cov khoom, khiav ceev thiab ruaj khov;
5
Dawb ether yog tsis meej, tsis muaj tshuaj lom, thiab muaj cov biocompatibility zoo. Ntawm lawv, Carboxymethyl cellulose (CMC) muaj "Industrial Monosodium Glutamate"
Npe nrov npe.
1.2.3.1 zaj duab xis tsim
Kev kawm qib siab etherification ether muaj ib qho muaj txiaj ntsig zoo ntawm nws cov ntawv ua yeeb yaj kiab xws li kev ua yeeb yam zoo li kev ua yeeb yam thiab kev sib tham. Cellulose ether
Vim nws cov kws kho tshuab zoo zog thiab kev sib raug zoo nrog ntau yam Resins, nws tuaj yeem siv rau hauv cov yeeb yaj kiab yas, cov nplaum thiab lwm yam ntaub ntawv.
khoom npaj.
1.2.3.2 solubility
Vim tias muaj cov pab pawg hydroxyl ntawm lub nplhaib ntawm cov pa-muaj cov qab zib, cellulose muaj cov neeg muaj kev pab muaj dej solubility zoo dua. thiab
Ua raws li cov cellulose ether hloov chaw thiab cov degree hloov chaw, tseem muaj kev xaiv sib txawv rau cov kuab tshuaj organic.
1.2.3.3 thickening
Cellulose ether yog yaj nyob rau hauv daim ntawv ntawm collegoid, nyob rau qib polymerization ntawm cellulose ntawm cellulose
Viscosity ntawm ether daws. Tsis zoo li cov kua dej xyoo tshiab, lub viscosity ntawm cellulose ether cov kev daws teeb meem hloov nrog shear zog, thiab
Vim yog cov qauv ntawm macromolecules, lub viscosity ntawm kev daws teeb meem sai nrog kev nce ntawm cov ntsiab lus ether, txawm li cas los xij kev daws qhov tshuaj viscosity
Viscosity kuj tseem poob sai nrog kev nce kub nce [33].
1.2.3.4 Dutradability
Lub cellulose ether daws yaj nyob rau hauv dej rau ib lub sij hawm yuav cog cov kab mob thiab rhuav tshem cov kab mob enzyme thiab theem ete.
Cov uas nyob ib sab unsubstituted li glucose nyob rau hauv ib txwm bonds, yog li txo tus txheeb ze molecular loj ntawm macromolecule. Yog li ntawd, cellulose muaj kev hais ua
Kev khaws cia ntawm cov kev daws teeb meem yuav tsum muaj kev sib ntxiv ntawm qee qhov ntawm cov tshuaj txuag.
Tsis tas li ntawd, cellulose muaj cov neeg muaj ntau yam xws li cov haujlwm saum npoo av, ionic kev ua si, ua npuas ncauj, ua npuas ncauj
Gel txiav txim. Vim tias cov khoom no, cov kws kho mob cellulose tau siv hauv textiles, papermaking, hluavtaws tshuaj ntxuav, tshuaj pleev ib ce, tshuaj,
Nws yog dav siv nyob rau hauv ntau thaj teb.
1.3 Taw qhia kom cog cov khoom nyoos
Los ntawm cov ntsiab lus ntawm 1.2 cellulose ether, nws tuaj yeem pom tau tias cov khoom siv ether yog tsuas yog cellulose cellulose, thiab ib qho ntawm cov ntsiab lus ntawm cov ncauj lus no
Nws yog kom siv cellulose muab rho tawm los ntawm cov khoom nyoos los ntawm cov ntaub ntawv raw los hloov cov xov tooj cua paj ntoo los npaj cellulose ether. Cov hauv qab no yog cov lus qhia luv luv rau cov nroj tsuag
cov khoom siv.
Raws li cov peev txheej xws li roj, thee thiab roj thiab cov khoom siv hluav taws xob raws li lawv, cov yeeb yaj kiab fiber ntau, tseem yuav muaj kev txwv ntau zuj zus. Nrog kev txhim kho kev txuas ntxiv ntawm cov zej zog thiab cov teb chaws thoob ntiaj teb (tshwj xeeb yog
Nws yog lub tebchaws tsim tsim tau) uas them rau qhov teeb meem ntawm kev muaj kuab paug ib puag ncig. Ntuj cellulose muaj biodegradability thiab ib puag ncig kev sib koom tes.
Nws yuav maj mam dhau los ua lub hauv paus tseem ceeb.
Lub Sijhawm Post: Sep-26-2022