Kev npaj ntawm Hydroxyethyl Cellulose

Hydroxyethyl Cellulose (HEC) feem ntau yog npaj los ntawm kev hloov kho tshuaj hu ua etherification, qhov twg hydroxyethyl pawg tau nkag mus rau hauv cov pob txha cellulose. Ntawm no yog ib qho piv txwv ntawm cov txheej txheem npaj:

1. Kev xaiv ntawm Cellulose Source:

• Cellulose, ib tug natural polymer pom nyob rau hauv cov nroj tsuag, pab raws li cov khoom pib rau synthesis ntawm HEC. Feem ntau qhov chaw ntawm cellulose muaj xws li ntoo pulp, paj rwb linters, thiab lwm yam fibers cog cov ntaub ntawv.

2. Ua kom Cellulose:

• Lub cellulose qhov chaw yog thawj zaug ua kom nws cov reactivity thiab nkag tau mus rau tom ntej etherification cov tshuaj tiv thaiv. Txoj kev ua kom muaj xws li kev kho alkaline lossis o hauv cov kuab tshuaj tsim nyog.

3. Etherification Reaction:

• Cov activated cellulose yog tom qab ntawd raug rau cov tshuaj tiv thaiv etherification nrog ethylene oxide (EO) los yog ethylene chlorohydrin (ECH) nyob rau hauv muaj alkaline catalysts xws li sodium hydroxide (NaOH) los yog potassium hydroxide (KOH).

4. Taw qhia ntawm Hydroxyethyl Pawg:

• Thaum lub sij hawm etherification cov tshuaj tiv thaiv, hydroxyethyl pawg (-CH2CH2OH) los ntawm cov ethylene oxide molecule yog nkag mus rau hauv cellulose qaum, hloov ib co ntawm cov hydroxyl (-OH) pawg nyob rau hauv lub cellulose molecule.

5. Kev tswj cov kev mob tshwm sim:

• Cov tshuaj tiv thaiv kab mob, suav nrog qhov kub, siab, lub sijhawm tshuaj tiv thaiv, thiab cov catalyst concentration, ua tib zoo tswj kom ua tiav qhov kev xav tau ntawm kev hloov pauv (DS) ntawm pawg hydroxyethyl ntawm cov pob txha cellulose.

6. Neutralization thiab ntxuav:

• Tom qab cov tshuaj tiv thaiv etherification, qhov tshwm sim HEC cov khoom yog nruab nrab kom tshem tawm cov catalyst ntau dhau thiab kho cov pH. Tom qab ntawd nws yuav tsum tau ntxuav nrog dej kom tshem tawm cov khoom siv los ntawm cov khoom siv, cov khoom tsis zoo, thiab cov impurities.

7. Purification thiab ziab:

• Cov khoom siv HEC purified yog feem ntau lim, centrifuged, los yog qhuav kom tshem tawm cov seem seem thiab tau txais qhov xav tau qhov loj me thiab daim ntawv (hmoov lossis granules). Cov kauj ruam ua kom huv ntxiv tuaj yeem ua haujlwm yog tias tsim nyog.

8. Yam ntxwv thiab Kev Tswj Xyuas Zoo:

• Cov khoom HEC kawg yog tus cwj pwm siv ntau yam kev tshuaj ntsuam xyuas los ntsuas nws cov khoom, suav nrog qib kev hloov pauv, viscosity, molecular hnyav faib, thiab purity. Kev tswj xyuas kev ua tau zoo yog siv los xyuas kom meej thiab ua raws li cov lus qhia tshwj xeeb.

9. Ntim thiab Cia:

• Cov khoom HEC tau ntim rau hauv cov thawv tsim nyog thiab khaws cia nyob rau hauv kev tswj xyuas kom tsis txhob degradation thiab tswj nws qhov ruaj khov. Daim ntawv lo thiab cov ntaub ntawv raug muab los ua kom yooj yim tuav, khaws cia, thiab siv.

Hauv cov ntsiab lus, kev npaj ntawm Hydroxyethyl Cellulose (HEC) suav nrog etherification ntawm cellulose nrog ethylene oxide lossis ethylene chlorohydrin raws li kev tswj xyuas, ua raws li kev ua haujlwm nruab nrab, ntxuav, ntxuav, thiab ziab kom qhuav. Cov khoom ua tau HEC yog cov dej-soluble polymer nrog cov khoom tshwj xeeb thiab ntau yam kev siv hauv ntau yam lag luam.