Hydroxyethyl Methyl Cellulose

Cellulose ether yog cov khoom siv dav siv polymer zoo tshuaj ua los ntawm ntuj polymer cellulose los ntawm kev kho tshuaj. Tom qab tsim cov cellulose nitrate thiab cellulose acetate nyob rau hauv lub xyoo pua 19th, chemists tau tsim ib tug series ntawm cellulose derivatives ntawm ntau cellulose ethers, thiab tshiab daim ntawv thov teb tau nrhiav tsis tu ncua, muaj ntau yam kev lag luam sectors. Cellulose ether khoom xws li sodium carboxymethyl cellulose (CMC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl hydroxyethyl cellulose (MHEC) thiab methyl hydroxypropyl cellulose (MHPC) thiab lwm yam cellulose ethers yog hu ua "kev lag luam monosodium glutamate" thiab tau siv dav hauv cov roj drilling, kev tsim kho, txheej, khoom noj, tshuaj thiab tshuaj txhua hnub.

Hydroxyethylmethylcellulose(MHEC) yog cov hmoov tsis muaj ntxhiab, tsis qab, tsis muaj tshuaj lom cov hmoov dawb uas tuaj yeem yaj hauv dej txias los tsim cov kua nplaum pob tshab. Nws muaj cov yam ntxwv ntawm thickening, khi, dispersing, emulsifying, film-forming, suspending, adsorbing, gelling, nto active, tuav noo noo thiab tiv thaiv colloid. Vim yog lub ntsej muag ua haujlwm ntawm cov tshuaj aqueous, nws tuaj yeem siv los ua cov tshuaj tiv thaiv colloidal, emulsifier thiab dispersant. Hydroxyethyl methylcellulose aqueous tov muaj hydrophilicity zoo thiab yog cov dej tuav tus neeg sawv cev zoo. Vim tias hydroxyethyl methylcellulose muaj cov pab pawg hydroxyethyl, nws muaj peev xwm los tiv thaiv mildew, zoo viscosity stability thiab mildew tsis kam thaum lub sij hawm ntev cia.

Hydroxyethyl methylcellulose (HEMC) yog npaj los ntawm kev qhia ethylene oxide substituents (MS 0.3 ~ 0.4) rau hauv methylcellulose (MC), thiab nws cov ntsev kuj zoo dua li cov tsis hloov pauv polymers. Lub gelation kub ntawm methylcellulose kuj siab dua li ntawm MC.

Qauv:

Feature:

Cov yam ntxwv tseem ceeb ntawm hydroxyethyl methylcellulose (HEMC) yog:

1. Solubility: Soluble hauv dej thiab qee cov organic solvents. HEMC tuaj yeem yaj hauv dej txias. Nws qhov siab tshaj plaws concentration tsuas yog txiav txim siab los ntawm viscosity. Solubility sib txawv nrog viscosity. Qhov qis dua qhov viscosity, qhov ntau dua qhov solubility.
2. Cov khoom siv ntsev: HEMC cov khoom tsis yog-ionic cellulose ethers thiab tsis yog polyelectrolytes, yog li lawv muaj kev ruaj khov nyob rau hauv aqueous daws thaum hlau ntsev los yog organic electrolytes muaj, tab sis ntau ntxiv ntawm electrolytes yuav ua rau gelation thiab nag lossis daus.
3. Deg kev ua si: Vim lub nto active muaj nuj nqi ntawm cov aqueous tov, nws yuav siv tau raws li ib tug colloidal tiv thaiv tus neeg saib xyuas, emulsifier thiab dispersant.
4. Thermal gel: Thaum lub aqueous tov ntawm HEMC cov khoom yog rhuab mus rau ib tug tej yam kub thiab txias, nws yuav opaque, gels, thiab precipitates, tab sis thaum nws yog tsis tu ncua txias, nws rov qab mus rau lub qub tshuaj xeev, thiab qhov kub ntawm qhov no gel thiab nag lossis daus. tshwm sim yog tsuas yog nyob ntawm lawv cov roj nplua nyeem, ncua kev pabcuam, kev tiv thaiv colloids, emulsifiers thiab lwm yam.
5. Metabolism inert thiab tsis muaj ntxhiab thiab tsw: HEMC yog dav siv nyob rau hauv cov zaub mov thiab tshuaj vim hais tias nws yuav tsis tau metabolized thiab tsis muaj ntxhiab thiab tsw.
6. Mildew kuj: HEMC muaj cov kab mob mildew kuj zoo thiab zoo viscosity stability thaum lub sij hawm ntev cia.
7. PH stability: Lub viscosity ntawm aqueous tov ntawm HEMC cov khoom yog tsis tshua muaj cuam tshuam los ntawm acid los yog alkali, thiab pH tus nqi kuj tseem ruaj khov nyob rau hauv thaj tsam ntawm 3.0 txog 11.0.

Daim ntawv thov:

Hydroxyethyl methylcellulose tuaj yeem siv los ua tus neeg saib xyuas kev tiv thaiv colloidal, emulsifier thiab dispersant vim nws qhov ua haujlwm saum npoo av hauv cov kua dej. Nws daim ntawv thov piv txwv yog raws li nram no:

1. Cov nyhuv ntawm hydroxyethyl methylcellulose rau kev ua haujlwm ntawm cov cement. Hydroxyethyl methylcellulose yog ib qho tsis muaj ntxhiab, tsis qab, tsis muaj tshuaj lom cov hmoov dawb uas tuaj yeem yaj hauv dej txias los tsim cov kua nplaum pob tshab. Nws muaj cov yam ntxwv ntawm thickening, khi, dispersing, emulsifying, film-forming, suspending, adsorbing, gelling, nto active, tuav noo noo thiab tiv thaiv colloid. Txij li thaum cov tshuaj aqueous muaj qhov chaw ua haujlwm, nws tuaj yeem siv los ua tus neeg saib xyuas colloidal, emulsifier thiab dispersant. Hydroxyethyl methylcellulose aqueous tov muaj hydrophilicity zoo thiab yog cov dej tuav tus neeg sawv cev zoo.
2. Cov xim pleev xim nrog qhov yooj yim yog npaj, uas yog ua los ntawm cov khoom siv raw hauv qab no hauv qhov hnyav: 150-200 g ntawm dej deionized; 60-70 g ntawm ntshiab acrylic emulsion; 550-650 g ntawm calcium hnyav; 70-90 g ntawm talcum hmoov; 30-40 g ntawm cellulose aqueous tov; 10-20g lignocellulose aqueous tov; 4-6g film-forming pab; 1.5-2.5g antiseptic thiab bactericide; 1.8-2.2g dispersant; 3.5-4.5g; Ethylene glycol 9-11g; Cov tshuaj hydroxyethyl methylcellulose aqueous yog tsim los ntawm dissolving 2-4% hydroxyethyl methylcellulose hauv dej; Lub lignocellulose aqueous tov yog ua los ntawm 1-3% Lignocellulose yog tsim los ntawm dissolving hauv dej.

Kev npaj:

Ib txoj kev npaj ntawm hydroxyethyl methylcellulose, txoj kev yog siv cov paj rwb refined ua raw khoom thiab ethylene oxide ua tus neeg sawv cev etherification los npaj hydroxyethyl methylcellulose. Qhov hnyav ntawm cov ntaub ntawv raw rau kev npaj hydroxyethyl methyl cellulose yog raws li nram no: 700-800 qhov chaw ntawm toluene thiab isopropanol sib tov ua hnyav, 30-40 qhov chaw ntawm dej, 70-80 qhov chaw ntawm sodium hydroxide, 80-85 qhov chaw ntawm refined paj rwb, nplhaib 20-28 qhov chaw ntawm oxyethane, 80-90 qhov chaw ntawm methyl chloride, 16-19 qhov chaw ntawm glacial acetic acid; cov kauj ruam tshwj xeeb yog:

Thawj kauj ruam, nyob rau hauv cov tshuaj tiv thaiv kettle, ntxiv toluene thiab isopropanol sib tov, dej, thiab sodium hydroxide, kub mus txog 60-80 ° C, sov so rau 20-40 feeb;

Qhov thib ob kauj ruam, alkalization: txias cov ntaub ntawv saum toj no rau 30-50 ° C, ntxiv cov paj rwb refined, tshuaj tsuag cov toluene thiab isopropanol sib tov hnyav, tso nws mus rau 0.006Mpa, sau nitrogen rau 3 hloov, thiab nqa tawm tom qab hloov Alkalinization, lub alkalization tej yam kev mob yog: lub sij hawm alkalization yog 2 teev, thiab alkalization kub yog 30 ° C mus rau 50 ° C;

Qhov thib peb kauj ruam, etherification: tom qab alkalization tiav, lub reactor raug tshem tawm mus rau 0.05-0.07MPa, thiab ethylene oxide thiab methyl chloride ntxiv rau 30-50 feeb; thawj theem ntawm etherification: 40-60 ° C, 1.0-2.0 Teev, lub siab tswj ntawm 0.15 thiab 0.3Mpa; theem ob ntawm etherification: 60 ~ 90 ℃, 2.0 ~ 2.5 teev, lub siab tswj ntawm 0.4 thiab 0.8Mpa;

Cov kauj ruam thib plaub, kev ua kom tsis zoo: Ntxiv cov ntsuas glacial acetic acid ua ntej rau nag lossis daus, nias rau hauv cov khoom siv etherified rau neutralization, nce qhov kub ntawm 75-80 ° C rau nag lossis daus, kub nce mus rau 102 ° C, thiab pH. tus nqi yog 6 Thaum 8 teev, lub desolventization tiav; lub tank desolventization yog ntim nrog dej kais dej kho los ntawm cov khoom siv rov qab osmosis ntawm 90 ° C txog 100 ° C;

Kauj ruam tsib, centrifugal ntxuav: cov khoom nyob rau hauv lub thib plaub kauj ruam yog centrifuged los ntawm ib tug kab rov tav ntsia hlau centrifuge, thiab cov khoom sib cais yog xa mus rau lub tank ntxhua khaub ncaws uas muaj dej kub ua ntej ntxuav cov khoom;

Kauj ruam thib rau, centrifugal kom qhuav: cov khoom ntxuav yog xa mus rau hauv lub tshuab ziab khaub ncaws los ntawm kab rov tav ntsia hlau centrifuge, thiab cov khoom yog qhuav ntawm 150-170 ° C, thiab cov khoom qhuav yog crushed thiab ntim.

Piv nrog rau cov khoom siv cellulose ether uas twb muaj lawm, qhov kev tsim tawm tam sim no siv ethylene oxide ua tus neeg sawv cev etherification los npaj hydroxyethyl methyl cellulose, uas muaj peev xwm tiv thaiv pwm zoo vim muaj cov pab pawg hydroxyethyl. Nws muaj viscosity zoo stability thiab mildew tsis kam thaum lub sij hawm ntev cia. Nws tuaj yeem siv tsis tau lwm cov cellulose ethers.