Methylcellulose (MC) thiab carboxymethylcellulose (CMC) yog ob hom cellulose derivatives, dav siv hauv cov zaub mov, tshuaj, kev tsim kho, kev lag luam tshuaj thiab lwm yam. Txawm hais tias lawv tag nrho cov tshuaj hloov kho los ntawm ntuj cellulose, muaj qhov sib txawv tseem ceeb hauv cov qauv tshuaj, lub cev thiab tshuaj lom neeg, thiab kev siv.
1. Cov qauv tshuaj thiab cov txheej txheem kev npaj
Methylcellulose yog tsim los ntawm reacting cellulose nrog methyl chloride (los yog methanol) nyob rau hauv alkaline tej yam kev mob. Thaum lub sijhawm txheej txheem no, ib feem ntawm pawg hydroxyl (-OH) hauv cov cellulose molecules tau hloov los ntawm methoxy pawg (-OCH₃) los ua methylcellulose. Qhov degree ntawm kev hloov pauv (DS, tus naj npawb ntawm cov hloov pauv hauv ib chav tsev piam thaj) ntawm methylcellulose txiav txim siab nws lub cev thiab tshuaj lom neeg, xws li solubility thiab viscosity.
Carboxymethylcellulose yog tsim los ntawm reacting cellulose nrog chloroacetic acid nyob rau hauv alkaline tej yam kev mob, thiab cov hydroxyl pawg yog hloov los ntawm carboxymethyl (-CH₂COOH). Qhov degree ntawm kev hloov pauv thiab degree ntawm polymerization (DP) ntawm CMC cuam tshuam rau nws cov solubility thiab viscosity hauv dej. CMC feem ntau muaj nyob rau hauv daim ntawv ntawm sodium ntsev, hu ua sodium carboxymethylcellulose (NaCMC).
2. Lub cev thiab tshuaj muaj zog
Solubility: Methylcellulose yaj hauv dej txias, tab sis poob solubility thiab tsim cov gel hauv dej kub. Qhov no thermal reversibility enables nws siv raws li ib tug thickener thiab gelling tus neeg sawv cev nyob rau hauv kev ua zaub mov. CMC yog soluble nyob rau hauv ob qho tib si dej txias thiab kub, tab sis viscosity ntawm nws cov tshuaj txo qis thaum qhov kub nce.
Viscosity: Lub viscosity ntawm ob qho tib si cuam tshuam los ntawm qib kev hloov pauv thiab kev daws teeb meem. Lub viscosity ntawm MC thawj zaug nce thiab tom qab ntawd txo qis thaum kub nce, thaum lub viscosity ntawm CMC txo qis thaum kub nce. Qhov no muab lawv tus kheej zoo nyob rau hauv ntau yam kev siv.
pH stability: CMC tseem nyob ruaj khov tshaj pH ntau yam, tshwj xeeb tshaj yog nyob rau hauv alkaline tej yam kev mob, uas ua rau nws nrov heev raws li ib tug stabilizer thiab thickener nyob rau hauv cov zaub mov thiab tshuaj. MC yog qhov ruaj khov nyob rau hauv nruab nrab thiab me ntsis alkaline tej yam kev mob, tab sis yuav degrade nyob rau hauv muaj zog acids los yog alkalis.
3. Cov chaw thov
Kev lag luam khoom noj khoom haus: Methylcellulose feem ntau siv rau hauv cov khoom noj ua cov thickener, emulsifier thiab stabilizer. Piv txwv li, nws tuaj yeem ua raws li qhov saj thiab kev ntxhib los mos ntawm cov rog thaum tsim cov khoom noj muaj roj tsawg. Carboxymethylcellulose yog siv dav hauv cov dej haus, cov khoom ci thiab cov khoom siv mis nyuj ua cov thickener thiab stabilizer los tiv thaiv cov dej sib cais thiab txhim kho saj.
Kev lag luam kws tshuaj: Methylcellulose yog siv rau hauv kev npaj cov tshuaj ntsiav tshuaj raws li ib tug binder thiab disintegrant, thiab kuj yog ib tug lubricant thiab tiv thaiv tus neeg sawv cev, xws li nyob rau hauv ophthalmic qhov muag tee raws li ib tug kua muag hloov. CMC yog dav siv nyob rau hauv cov tshuaj vim nws zoo biocompatibility, xws li kev npaj ntawm sustained-tso tshuaj thiab adhesives nyob rau hauv qhov muag tee.
Kev tsim kho thiab tshuaj lom neeg kev lag luam: MC yog siv dav hauv cov khoom siv hauv tsev ua cov thickener, dej tuav tus neeg sawv cev thiab cov nplaum rau cov cement thiab gypsum. Nws tuaj yeem txhim kho kev tsim kho kev ua haujlwm thiab qhov zoo ntawm cov ntaub ntawv. CMC feem ntau siv los kho cov av nkos hauv cov roj av mining, slurry hauv textile printing thiab dyeing, txheej txheej ntawm ntawv, thiab lwm yam.
4. Kev nyab xeeb thiab kev tiv thaiv ib puag ncig
Ob leeg raug suav hais tias muaj kev nyab xeeb rau kev siv khoom noj thiab tshuaj, tab sis lawv cov peev txheej thiab cov txheej txheem tsim khoom yuav muaj kev cuam tshuam sib txawv ntawm ib puag ncig. Cov ntaub ntawv raw ntawm MC thiab CMC yog muab los ntawm ntuj cellulose thiab biodegradable, yog li lawv ua tau zoo nyob rau hauv cov nqe lus ntawm ib puag ncig tus phooj ywg. Txawm li cas los xij, lawv cov txheej txheem tsim khoom yuav suav nrog cov kuab tshuaj thiab cov tshuaj reagents, uas yuav muaj qee yam cuam tshuam rau ib puag ncig.
5. Nqe thiab kev lag luam xav tau
Vim muaj cov txheej txheem ntau lawm, tus nqi tsim khoom ntawm methylcellulose feem ntau yog siab dua, yog li nws cov nqi lag luam kuj tseem siab dua carboxymethylcellulose. CMC feem ntau muaj kev lag luam xav tau ntau dua vim nws daim ntawv thov dav dua thiab cov nqi tsim khoom qis dua.
Txawm hais tias methylcellulose thiab carboxymethylcellulose yog ob qho tib si derivatives ntawm cellulose, lawv muaj qhov sib txawv tseem ceeb hauv cov qauv, khoom, kev siv thiab kev lag luam xav tau. Methylcellulose feem ntau yog siv rau hauv cov khoom noj, tshuaj thiab cov khoom siv hauv tsev vim nws qhov tshwj xeeb thermal reversibility thiab siab viscosity tswj. Carboxymethyl cellulose tau siv dav hauv cov khoom noj, tshuaj, petrochemical, textile thiab lwm yam lag luam vim nws zoo heev solubility, viscosity hloov thiab dav pH adaptability. Qhov kev xaiv ntawm cellulose derivative nyob ntawm qhov kev thov tshwj xeeb scenario thiab xav tau.
Post lub sij hawm: Aug-20-2024