Polyanionic cellulose (PAC) yog cov dej-soluble cellulose derivative uas muaj ntau yam kev siv nyob rau hauv ntau yam lag luam, tshwj xeeb tshaj yog nyob rau hauv lub teb ntawm drilling kua nyob rau hauv cov roj thiab roj kev lag luam. Nws yog lub npe hu rau nws zoo heev rheological zog, siab stability thiab compatibility nrog rau lwm yam additives. Kev tsim cov polyanionic cellulose suav nrog ob peb kauj ruam, suav nrog kev rho tawm cellulose, tshuaj hloov kho, thiab ua kom huv.
1. Cellulose extraction:
Cov khoom pib rau polyanionic cellulose yog cellulose, ib tug natural polymer pom nyob rau hauv cov nroj tsuag cell phab ntsa. Cellulose tuaj yeem muab tau los ntawm cov khoom siv cog ntoo sib txawv, xws li ntoo pulp, paj rwb linters, lossis lwm yam nroj tsuag fibrous. Cov txheej txheem extraction muaj cov kauj ruam hauv qab no:
A. Raw khoom npaj:
Cov ntaub ntawv cog qoob loo xaiv tau raug kho kom tshem tawm cov impurities xws li lignin, hemicellulose thiab pectin. Qhov no feem ntau ua tiav los ntawm kev sib xyaw ua ke ntawm kev kho tshuab thiab tshuaj lom neeg.
b. Pulping:
Cov khoom siv pretreated yog ces pulped, txheej txheem uas zom cellulose fibers. Cov txheej txheem pulping feem ntau suav nrog kraft pulping thiab sulfite pulping, txhua tus muaj nws tus kheej zoo thiab qhov tsis zoo.
C. Kev sib cais ntawm cellulose:
Cov khoom siv pulp yog ua tiav los cais cov cellulosic fibers. Qhov no feem ntau suav nrog kev ntxuav thiab tshuaj dawb kom tau txais cov khoom siv cellulosic ntshiab.
2. Kev hloov kho tshuaj:
Thaum cov cellulose tau txais, nws tau hloov kho tshuaj los qhia cov pab pawg anionic, hloov mus rau hauv polyanionic cellulose. Ib txoj hauv kev uas feem ntau siv rau lub hom phiaj no yog etherification.
A. Etherification:
Etherification suav nrog cov tshuaj tiv thaiv ntawm cellulose nrog tus neeg sawv cev etherifying los qhia txog kev sib txuas ntawm ether. Nyob rau hauv cov ntaub ntawv ntawm polyanionic cellulose, carboxymethyl pawg feem ntau yog qhia. Qhov no yog ua tiav los ntawm cov tshuaj tiv thaiv nrog sodium monochloroacetate nyob rau hauv lub xub ntiag ntawm ib qho yooj yim catalyst.
b. Cov tshuaj tiv thaiv Carboxymethylation:
Cov tshuaj tiv thaiv carboxymethylation cuam tshuam nrog kev hloov ntawm hydrogen atoms ntawm hydroxyl pawg ntawm cellulose nrog carboxymethyl pawg. Cov tshuaj tiv thaiv no tseem ceeb heev rau kev qhia txog cov nqi anionic ntawm cov pob txha cellulose.
C. neutralize:
Tom qab carboxymethylation, cov khoom yog neutralized los hloov cov carboxymethyl pawg rau carboxylate ions. Cov kauj ruam no yog qhov tseem ceeb rau kev ua cov polyanionic cellulose dej-soluble.
3. Purification:
Hloov kho cellulose yog tom qab ntxuav kom tshem tawm cov khoom lag luam, cov tshuaj tsis muaj tshuaj lom, thiab cov impurities uas yuav cuam tshuam rau nws cov kev ua tau zoo hauv ib daim ntawv thov tshwj xeeb.
A. ntxuav:
Cov khoom raug ntxuav kom huv si kom tshem tawm cov reactants ntau dhau, ntsev thiab lwm yam impurities. Dej feem ntau yog siv rau lub hom phiaj no.
b. Kev ziab:
Cov purified polyanionic cellulose yog ces qhuav kom tau cov khoom kawg nyob rau hauv hmoov los yog granular daim ntawv.
4. Kev tswj kom zoo:
Kev tswj xyuas kev ua tau zoo yog siv thoob plaws hauv cov txheej txheem tsim khoom kom ntseeg tau tias cov txiaj ntsig polyanionic cellulose ua tau raws li qhov xav tau tshwj xeeb. Qhov no suav nrog kev ntsuas qhov hnyav molecular, qib ntawm kev hloov pauv thiab lwm yam tsis raug.
5. Daim ntawv thov:
Polyanionic cellulose muaj daim ntawv thov nyob rau hauv ntau yam lag luam, feem ntau nyob rau hauv drilling kua systems nyob rau hauv cov roj thiab roj sector. Nws ua raws li tackifier, kua dej poob tswj tus neeg saib xyuas thiab shale inhibitor, txhim kho tag nrho cov kev ua tau zoo ntawm cov dej drilling. Lwm daim ntawv thov suav nrog cov zaub mov thiab tshuaj lag luam uas nws cov dej solubility thiab rheological khoom muaj qhov zoo.
Polyanionic cellulose yog ntau yam thiab muaj txiaj ntsig ntawm cellulose derivative uas nws cov khoom yuav tsum tau ua raws li cov kauj ruam zoo. Kev rho tawm ntawm cellulose los ntawm cov khoom cog, tshuaj hloov kho los ntawm etherification, purification thiab kev tswj kom zoo yog qhov tseem ceeb ntawm cov txheej txheem tsim khoom. Cov txiaj ntsig polyanionic cellulose yog cov khoom siv tseem ceeb hauv ntau hom kev lag luam, pab txhim kho kev ua haujlwm thiab kev ua haujlwm ntawm cov qauv sib txawv. Raws li kev lag luam txuas ntxiv txhim kho, kev thov rau cov khoom tshwj xeeb cellulose derivatives xws li polyanionic cellulose yuav tsum loj hlob, tsav tsheb txuas ntxiv kev tshawb fawb thiab kev loj hlob hauv cellulose hloov kho thev naus laus zis thiab kev siv.
Post lub sij hawm: Dec-26-2023