Cov txheej txheem rau kev tsim cov methyl cellulose ether

Kev tsim khoom ntawmmethyl cellulose etherKoom nrog cov tshuaj hloov kho ntawm cellulose los ntawm etherification cov tshuaj tiv thaiv. Methyl cellulose (MC) yog dej-soluble cellulose ether dav siv nyob rau hauv ntau yam lag luam. Ntawm no yog cov lus qhia dav dav ntawm cov txheej txheem rau kev tsim cov methyl cellulose ether:

1. Xaiv Cellulose Source:

• Cov txheej txheem pib nrog kev xaiv ntawm cellulose qhov chaw, feem ntau muab tau los ntawm cov ntoo pulp lossis paj rwb. Qhov chaw cellulose raug xaiv raws li qhov xav tau ntawm cov khoom kawg methyl cellulose.

2. Pulping:

• Cov khoom siv cellulose xaiv tau dhau los ua pulping, txheej txheem uas rhuav tshem cov fibers rau hauv daim ntawv tswj tau ntau dua. Pulping tuaj yeem ua tiav los ntawm kev siv tshuab lossis tshuaj.

3. Ua kom Cellulose:

• Lub pulped cellulose yog ces qhib los ntawm kev kho nws nrog ib tug alkaline tov. Cov kauj ruam no yog txhawm rau o ntawm cov cellulose fibers, ua rau lawv ntau reactive thaum lub sij hawm tom ntej etherification cov tshuaj tiv thaiv.

4. Etherification Reaction:

• Cov activated cellulose tau txais etherification, qhov twg ether pawg, nyob rau hauv cov ntaub ntawv no, methyl pawg, yog nkag mus rau cov hydroxyl pawg ntawm cellulose polymer saw.
• Cov tshuaj tiv thaiv etherification suav nrog kev siv cov tshuaj methylating xws li sodium hydroxide thiab methyl chloride lossis dimethyl sulfate. Cov xwm txheej tshuaj tiv thaiv, suav nrog qhov kub, siab, thiab lub sijhawm tshuaj tiv thaiv, tau ua tib zoo tswj kom ua tiav qhov kev xav tau ntawm kev hloov pauv (DS).

5. Neutralization thiab ntxuav:

• Tom qab cov tshuaj tiv thaiv etherification, cov khoom yog neutralized kom tshem tawm ntau tshaj alkali. Cov kauj ruam tom ntej ntxuav yog ua kom tshem tawm cov tshuaj seem thiab impurities.

6. Qhuav:

• Cov purified thiab methylated cellulose yog qhuav kom tau qhov kawg methyl cellulose ether khoom nyob rau hauv daim ntawv ntawm hmoov los yog granules.

7. 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. Qhov degree ntawm kev hloov pauv (DS) yog qhov ntsuas tseem ceeb uas tau saib xyuas thaum lub sijhawm tsim khoom.

8. Kev tsim thiab ntim:

• Tom qab ntawd cov methyl cellulose ether yog tsim nyob rau hauv ntau qib kom tau raws li cov kev cai ntawm ntau yam kev siv. Cov qib sib txawv yuav txawv ntawm lawv cov viscosity, particle loj, thiab lwm yam khoom.
• Cov khoom kawg yog ntim rau kev faib tawm.

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias cov xwm txheej tshwj xeeb thiab cov tshuaj reagents siv hauv cov tshuaj tiv thaiv etherification tuaj yeem sib txawv raws li cov chaw tsim khoom cov txheej txheem thiab cov khoom xav tau ntawm cov khoom methyl cellulose. Methyl cellulose pom cov ntawv thov hauv kev lag luam khoom noj, tshuaj, kev tsim kho, thiab lwm yam haujlwm vim nws cov dej-solubility thiab kev ua yeeb yaj kiab.