Methylhydroxyethylcellulose (MHEC) yog ib qho tseem ceeb hauv kev lag luam ntau yam, tshwj xeeb hauv kev tsim kho, tshuaj, thiab cov khoom siv tu tus kheej.Nws lub luag haujlwm tseem ceeb ua tus neeg saib xyuas dej ua rau nws tseem ceeb hauv kev siv xws li cov ntaub ntawv cementitious, tshuaj formulations, thiab tshuaj pleev ib ce.
1. Molecular Structure ntawm MHEC:
MHEC belongs rau cellulose ethers tsev neeg, uas yog derivatives ntawm cellulose - ib tug tshwm sim polymer pom nyob rau hauv lub cell phab ntsa ntawm cov nroj tsuag.MHEC yog synthesized los ntawm etherification ntawm cellulose, nyob rau hauv ob qho tib si methyl thiab hydroxyethyl pawg tau nkag mus rau hauv cellulose qaum.Qib ntawm kev hloov pauv (DS) ntawm cov pab pawg no txawv, cuam tshuam rau cov khoom ntawm MHEC xws li solubility, viscosity, thiab dej tuav peev xwm.
2. Solubility thiab Dispersion:
MHEC nthuav tawm zoo solubility hauv dej vim muaj cov pab pawg hydrophilic hydroxyethyl.Thaum dispersed nyob rau hauv dej, MHEC molecules undergo hydration, nrog dej molecules tsim hydrogen bonds nrog cov hydroxyl pawg nyob rau hauv lub cellulose qaum.Cov txheej txheem hydration no ua rau o ntawm MHEC hais thiab tsim cov kua nplaum los yog dispersion.
3. Dej Retention Mechanism:
Lub tshuab khaws dej ntawm MHEC muaj ntau yam thiab muaj ntau yam:
ib.Hydrogen Bonding: MHEC molecules muaj ntau pawg hydroxyl muaj peev xwm tsim cov hydrogen bonds nrog dej molecules.Qhov kev sib cuam tshuam no txhim kho cov dej khaws cia los ntawm kev tso dej hauv cov polymer matrix los ntawm hydrogen bonding.
b.o Muaj peev xwm o: Muaj ob qho tib si hydrophilic thiab hydrophobic pawg hauv MHEC tso cai rau nws o loj heev thaum raug dej.Raws li cov dej molecules nkag mus rau hauv lub network polymer, MHEC chains swell, tsim cov qauv zoo li gel uas khaws cov dej hauv nws cov matrix.
c.Capillary Action: Hauv kev tsim kho, MHEC feem ntau ntxiv rau cov khoom siv cementitious xws li mortar lossis pob zeb los txhim kho kev ua haujlwm thiab txo cov dej poob.MHEC ua haujlwm nyob rau hauv lub capillary pores ntawm cov ntaub ntawv no, tiv thaiv cov dej evaporation sai thiab tswj cov dej tsis sib xws.Qhov kev txiav txim capillary no ua tau zoo txhim kho dej thiab kho cov txheej txheem, ua rau txhim kho lub zog thiab ua haujlwm ntev ntawm cov khoom kawg.
d.Film-Forming Properties: Ntxiv nrog rau nws cov peev xwm khaws dej hauv cov kev daws teeb meem ntau, MHEC tuaj yeem tsim cov yeeb yaj kiab nyias thaum siv rau ntawm qhov chaw.Cov yeeb yaj kiab no ua cov teeb meem, txo cov dej los ntawm evaporation thiab muab kev tiv thaiv tiv thaiv kev hloov pauv ntawm cov dej noo.
4. Kev cuam tshuam ntawm Degree of Substitution (DS):
Qib ntawm kev hloov ntawm methyl thiab hydroxyethyl pawg ntawm cov pob txha cellulose cuam tshuam rau cov dej tuav cov khoom ntawm MHEC.Cov txiaj ntsig DS siab dua feem ntau ua rau muaj peev xwm khaws dej ntau dua vim tias muaj zog hydrophilicity thiab cov saw yooj yooj yim.Txawm li cas los xij, cov txiaj ntsig DS ntau dhau tuaj yeem ua rau muaj viscosity lossis gelation ntau dhau, cuam tshuam rau kev ua haujlwm thiab kev ua haujlwm ntawm MHEC hauv ntau daim ntawv thov.
5. Kev sib cuam tshuam nrog Lwm Cov Cheeb Tsam:
Nyob rau hauv cov formulations complex xws li tshuaj los yog cov khoom tu tus kheej, MHEC cuam tshuam nrog lwm cov khoom xyaw, nrog rau cov tshuaj nquag, surfactants, thiab thickeners.Cov kev sib cuam tshuam no tuaj yeem cuam tshuam tag nrho kev ruaj ntseg, viscosity, thiab kev ua tau zoo ntawm kev tsim.Piv txwv li, hauv cov tshuaj raug tshem tawm, MHEC tuaj yeem pab tshem tawm cov khoom xyaw nquag sib npaug thoob plaws hauv cov kua theem, tiv thaiv sedimentation lossis sib sau ua ke.
6. Kev txiav txim siab ib puag ncig:
Thaum MHEC yog biodegradable thiab feem ntau suav hais tias yog ib puag ncig tus phooj ywg, nws cov khoom lag luam yuav koom nrog cov txheej txheem tshuaj lom neeg uas tsim cov khoom pov tseg lossis cov khoom lag luam.Cov neeg tsim khoom tau nce ntxiv tshawb nrhiav cov txheej txheem tsim khoom kom ruaj khov thiab muab cov cellulose los ntawm cov khoom siv biomass txuas ntxiv kom txo tau qhov cuam tshuam ib puag ncig.
7. Cov lus xaus:
Methylhydroxyethylcellulose (MHEC) yog cov khoom siv dej ntau yam nrog cov ntawv thov sib txawv hauv ntau qhov kev lag luam.Nws cov qauv molecular, solubility, thiab kev cuam tshuam nrog dej ua kom nws khaws cov dej noo zoo, txhim kho kev ua haujlwm, thiab txhim kho kev ua haujlwm ntawm cov qauv.Kev nkag siab txog kev ua haujlwm ntawm MHEC yog qhov tseem ceeb rau kev txhim kho nws cov kev siv hauv kev siv sib txawv thaum xav txog yam xws li kev hloov pauv, kev sib raug zoo nrog lwm cov khoom xyaw, thiab kev xav txog ib puag ncig.
Post lub sij hawm: Mar-19-2024