Cellulose ethers thiab txoj kev tsim ib yam

Kev tsim tawm ntawmcellulose ethersMuaj kev hloov kho tshuaj lom neeg rau cellulose, uas ua rau cov derivatives nrog cov khoom tshwj xeeb. Cov hauv qab no yog cov ntsiab lus dav dav ntawm cov txheej txheem siv los tsim cov cellulose ethers:

1. Kev xaiv ntawm Cellulose Source:

• Cellulose ethers tuaj yeem muab tau los ntawm ntau qhov chaw xws li ntoo pulp, paj rwb linters, lossis lwm yam khoom siv cog. Kev xaiv ntawm cellulose qhov chaw tuaj yeem cuam tshuam cov yam ntxwv ntawm cov khoom siv cellulose ether kawg.

2. Pulping:

• Lub cellulose qhov chaw undergoes pulping kom zom cov fibers mus rau hauv ib daim ntawv tswj tau ntau dua. Pulping tuaj yeem ua tiav los ntawm kev siv tshuab, tshuaj, lossis kev sib xyaw ntawm ob txoj kev.

3. Purification:

• Lub pulped cellulose yog raug rau purification txheej txheem kom tshem tawm impurities, lignin, thiab lwm yam uas tsis yog-cellulosic Cheebtsam. Kev ua kom huv yog qhov tseem ceeb kom tau txais cov khoom zoo cellulose.

4. Ua kom Cellulose:

• Lub purified cellulose yog qhib los ntawm o nyob rau hauv ib tug alkaline tov. Cov kauj ruam no yog qhov tseem ceeb rau kev ua kom cov cellulose ntau reactive thaum lub sij hawm tom ntej etherification cov tshuaj tiv thaiv.

5. Etherification Reaction:

• Cov activated cellulose tau txais etherification, qhov twg ether pawg tau nkag mus rau hydroxyl pawg ntawm cellulose polymer saw. Cov tshuaj etherifying muaj xws li ethylene oxide, propylene oxide, sodium chloroacetate, methyl chloride, thiab lwm yam.
• Cov tshuaj tiv thaiv feem ntau yog ua raws li kev tswj hwm ntawm qhov kub, siab, thiab pH kom ua tiav qhov kev xav tau ntawm kev hloov pauv (DS) thiab kom tsis txhob muaj kev cuam tshuam sab nraud.

6. Neutralization thiab ntxuav:

• Tom qab cov tshuaj tiv thaiv etherification, cov khoom yog feem ntau neutralized kom tshem tawm cov reagents ntau dhau los yog cov khoom lag luam. Cov kauj ruam tom ntej ntxuav yog ua kom tshem tawm cov tshuaj seem thiab impurities.

7. Qhuav:

• Cov purified thiab etherified cellulose yog qhuav kom tau qhov kawg cellulose ether khoom nyob rau hauv hmoov los yog granular daim ntawv.

8. Kev Tswj Xyuas Zoo:

• Ntau yam kev tshuaj ntsuam xyuas, suav nrog nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, thiab chromatography, yog ua haujlwm rau kev tswj kom zoo. DS tau raug saib xyuas kom zoo sib xws.

9. Formulation thiab Application:

• Cov cellulose ether yog tom qab ntawd tsim rau hauv qib sib txawv kom tau raws li cov kev cai tshwj xeeb ntawm ntau daim ntawv thov. Cov cellulose ethers sib txawv yog tsim rau cov kev lag luam sib txawv, xws li kev tsim kho, tshuaj, khoom noj, txheej, thiab lwm yam.

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias cov txheej txheem tshwj xeeb thiab cov xwm txheej yuav txawv raws li qhov xav tau ntawm cov khoom siv cellulose ether thiab daim ntawv thov npaj. Cov neeg tsim khoom feem ntau ntiav cov txheej txheem tsim los tsim cov cellulose ethers nrog cov khoom tshwj xeeb tsim kom tau raws li cov kev xav tau ntawm ntau hom kev lag luam.