Carboxymethyl Cellulose (CMC) thiab methyl cellulose (MC) yog ob lub cellulose derivatives dav siv nyob rau hauv ntau industries. Txawm hais tias lawv yog ob qho tib si muab los ntawm ntuj cellulose, vim muaj kev hloov kho tshuaj sib txawv, CMC thiab MC muaj qhov sib txawv loj hauv cov qauv tshuaj, lub cev thiab tshuaj lom neeg, thiab daim ntawv thov.
1. Qhov chaw thiab cov ntsiab lus tseem ceeb
Carboxymethylcellulose (CMC) yog npaj los ntawm reacting ntuj cellulose nrog chloroacetic acid tom qab kho alkali. Nws yog anionic dej-soluble cellulose derivative. CMC feem ntau muaj nyob rau hauv daim ntawv ntawm sodium ntsev, yog li nws tseem hu ua Sodium Carboxymethyl Cellulose (Na-CMC). Vim nws zoo solubility thiab viscosity hloov muaj nuj nqi, CMC yog dav siv nyob rau hauv cov zaub mov, tshuaj, roj drilling, textile thiab ntawv industries.
Methylcellulose (MC) yog npaj los ntawm methylating cellulose nrog methyl chloride (los yog lwm yam methylating reagents). Nws yog non-ionic cellulose derivative. MC muaj cov khoom siv thermal gel, cov kev daws teeb meem thaum rhuab thiab yaj thaum txias. Vim nws cov khoom tshwj xeeb, MC tau siv dav hauv cov khoom siv hauv tsev, tshuaj npaj, txheej, zaub mov thiab lwm yam lag luam.
2. Cov qauv tshuaj
Lub hauv paus qauv ntawm CMC yog kev taw qhia ntawm ib pawg carboxymethyl (-CH2COOH) ntawm cov piam thaj chav tsev ntawm β-1,4-glucosidic bond ntawm cellulose. Cov pawg carboxyl no ua rau nws anionic. Cov qauv molecular ntawm CMC muaj ntau ntawm sodium carboxylate pawg. Cov pab pawg no tau yooj yim dissociated hauv dej, ua rau CMC molecules tsis zoo nqi, yog li muab nws zoo dej solubility thiab thickening zog.
Cov qauv molecular ntawm MC yog kev taw qhia ntawm methoxy pawg (–OCH3) rau hauv cov cellulose molecules, thiab cov methoxy pawg no hloov ib feem ntawm hydroxyl pawg hauv cellulose molecules. Tsis muaj ionized pawg hauv MC qauv, yog li nws tsis yog-ionic, txhais tau tias nws tsis cuam tshuam los yog raug nqi hauv kev daws teeb meem. Nws cov khoom tshwj xeeb thermal gel yog tshwm sim los ntawm muaj cov methoxy pawg.
3. Solubility thiab lub cev muaj zog
CMC muaj cov dej solubility zoo hauv dej thiab tuaj yeem yaj sai sai hauv dej txias los tsim cov kua dej ntshiab. Txij li nws yog anionic polymer, solubility ntawm CMC cuam tshuam los ntawm lub zog ionic thiab pH tus nqi ntawm cov dej. Nyob rau hauv ib puag ncig muaj ntsev los yog muaj zog acid, solubility thiab stability ntawm CMC yuav txo. Tsis tas li ntawd, qhov viscosity ntawm CMC yog qhov ruaj khov ntawm qhov kub sib txawv.
Lub solubility ntawm MC hauv dej nyob ntawm qhov kub thiab txias. Nws tuaj yeem yaj hauv dej txias tab sis yuav tsim ib lub gel thaum rhuab. Cov cuab yeej thermal gel no ua rau MC ua haujlwm tshwj xeeb hauv kev lag luam khoom noj thiab cov khoom siv hauv tsev. Lub viscosity ntawm MC txo qis thaum qhov kub nce, thiab nws muaj kev tiv thaiv zoo rau enzymatic degradation thiab stability.
4. Cov yam ntxwv viscosity
Lub viscosity ntawm CMC yog ib qho ntawm nws lub cev tseem ceeb tshaj plaws. Lub viscosity yog ze ze rau nws qhov hnyav molecular thiab qib ntawm kev hloov pauv. Lub viscosity ntawm CMC cov tshuaj muaj kev kho tau zoo, feem ntau ua rau cov viscosity siab dua ntawm qhov tsis tshua muaj siab (1% -2%), yog li nws feem ntau siv los ua cov thickener, stabilizer thiab suspending agent.
Lub viscosity ntawm MC kuj muaj feem xyuam rau nws qhov hnyav molecular thiab qib hloov pauv. MC nrog cov qib sib txawv ntawm kev hloov pauv muaj qhov sib txawv viscosity yam ntxwv. MC kuj muaj cov nyhuv thickening zoo nyob rau hauv cov tshuaj, tab sis thaum rhuab mus rau ib tug tej yam kub, cov tshuaj MC yuav gel. Cov cuab yeej gelling no tau siv dav hauv kev tsim kho kev lag luam (xws li gypsum, cement) thiab kev ua zaub mov (xws li thickening, zaj duab xis tsim, thiab lwm yam).
5. Cov chaw thov
CMC feem ntau yog siv los ua thickener, emulsifier, stabilizer, thiab tshem tawm tus neeg sawv cev hauv kev lag luam khoom noj. Piv txwv li, hauv dej khov, yogurt thiab txiv hmab txiv ntoo haus, CMC tuaj yeem tiv thaiv cov khoom sib cais thiab txhim kho saj thiab ruaj khov ntawm cov khoom. Hauv kev lag luam roj av, CMC yog siv los ua cov av nkos los pab tswj cov kua dej thiab cov kua dej poob ntawm cov dej drilling. Tsis tas li ntawd, CMC kuj tseem siv rau kev hloov pauv ntawm cov ntaub ntawv hauv kev lag luam ntawv thiab ua tus neeg sawv cev hauv kev lag luam textile.
MC yog dav siv nyob rau hauv kev tsim kho kev lag luam, tshwj xeeb tshaj yog nyob rau hauv qhuav mortars, pobzeb adhesives thiab putty hmoov. Raws li tus neeg sawv cev thickening thiab dej khaws cia, MC tuaj yeem txhim kho kev tsim kho thiab kev sib txuas lub zog. Hauv kev lag luam kws tshuaj, MC yog siv los ua cov ntsiav tshuaj binders, cov ntaub ntawv tso tawm thiab cov ntaub ntawv phab ntsa capsule. Nws cov khoom siv thermogelling pab tswj kev tso tawm hauv qee cov qauv. Tsis tas li ntawd, MC kuj tseem siv rau hauv kev lag luam khoom noj khoom haus ua cov thickener, stabilizer thiab emulsifier rau cov zaub mov, xws li kua ntses, txhaws, breads, thiab lwm yam.
6. Kev nyab xeeb thiab biodegradability
CMC suav hais tias yog khoom noj khoom haus zoo. Cov kev tshawb fawb toxicological dav dav tau pom tias CMC tsis muaj teeb meem rau tib neeg lub cev ntawm cov tshuaj pom zoo. Txij li thaum CMC yog ib qho derivative raws li ntuj cellulose thiab muaj biodegradability zoo, nws yog tus phooj ywg nyob rau hauv ib puag ncig thiab tuaj yeem degraded los ntawm cov kab mob.
MC kuj suav hais tias yog ib qho tshuaj ntxiv uas muaj kev nyab xeeb thiab siv dav hauv tshuaj, khoom noj thiab tshuaj pleev ib ce. Nws cov xwm txheej tsis-ionic ua rau nws ruaj khov hauv vivo thiab hauv vitro. Txawm hais tias MC tsis yog biodegradable li CMC, nws tseem tuaj yeem degraded los ntawm cov kab mob hauv cov kab mob tshwj xeeb.
Txawm hais tias carboxymethyl cellulose thiab methyl cellulose yog ob qho tib si muab los ntawm cov cellulose ntuj, lawv muaj cov yam ntxwv sib txawv hauv kev siv tswv yim vim lawv cov qauv tshuaj sib txawv, lub cev thiab daim ntawv thov. CMC yog dav siv nyob rau hauv cov zaub mov, tshuaj thiab kev lag luam teb vim nws cov dej zoo solubility, thickening thiab ncua kev kawm ntawv, thaum MC tuav ib tug tseem ceeb txoj hauj lwm nyob rau hauv kev tsim kho, tshuaj thiab zaub mov industries vim nws thermal gel zog thiab stability. Ob leeg muaj cov kev siv tshwj xeeb hauv kev lag luam niaj hnub, thiab ob qho tib si yog cov khoom ntsuab thiab ib puag ncig tus phooj ywg.
Post lub sij hawm: Oct-18-2024