Hydroxyethyl Methyl Cellulose

Cellulose ether jẹ ohun elo kemikali ti o dara julọ polima ti a lo lọpọlọpọ ti a ṣe lati inu cellulose polymer adayeba nipasẹ itọju kemikali. Lẹhin iṣelọpọ ti iyọ cellulose ati acetate cellulose ni ọrundun 19th, awọn onimọ-jinlẹ ti ṣe agbekalẹ lẹsẹsẹ ti awọn itọsẹ cellulose ti ọpọlọpọ awọn ethers cellulose, ati awọn aaye ohun elo tuntun ti ṣe awari nigbagbogbo, pẹlu ọpọlọpọ awọn apa ile-iṣẹ. Awọn ọja ether cellulose gẹgẹbi iṣuu soda carboxymethyl cellulose (CMC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl hydroxyethyl cellulose (MHEC) ati methyl hydroxypropyl cellulose (MHPC) ati awọn ethers cellulose miiran ni a mọ bi "Monosodium glutamate ile-iṣẹ" ati pe a ti lo ni lilo pupọ ni liluho epo, ikole, awọn aṣọ, ounjẹ, oogun ati awọn kemikali ojoojumọ.

Hydroxyethylmethylcellulose(MHEC) jẹ olfato, ti ko ni itọwo, lulú funfun ti ko ni majele ti o le tuka ninu omi tutu lati ṣe ojutu viscous ti o han gbangba. O ni awọn abuda ti o nipọn, abuda, pipinka, emulsifying, film-forming, suspending, adsorbing, gelling, dada ti nṣiṣe lọwọ, mimu ọrinrin ati idaabobo colloid. Nitori iṣẹ ṣiṣe dada ti ojutu olomi, o le ṣee lo bi oluranlowo aabo colloidal, emulsifier ati dispersant. Hydroxyethyl methylcellulose ojutu olomi ni hydrophilicity ti o dara ati pe o jẹ oluranlowo idaduro omi daradara. Nitori hydroxyethyl methylcellulose ni awọn ẹgbẹ hydroxyethyl, o ni agbara egboogi-imuwodu to dara, iduroṣinṣin iki ti o dara ati imuwodu resistance lakoko ipamọ igba pipẹ.

Hydroxyethyl methylcellulose (HEMC) ti wa ni ipese nipasẹ iṣafihan awọn ohun elo oxide ethylene (MS 0.3 ~ 0.4) sinu methylcellulose (MC), ati iyọdajẹ iyọ jẹ dara ju ti awọn polima ti a ko yipada. Iwọn gelation ti methylcellulose tun ga ju ti MC lọ.

Eto:

Ẹya ara ẹrọ:

Awọn abuda akọkọ ti hydroxyethyl methylcellulose (HEMC) jẹ:

1. Solubility: Tiotuka ninu omi ati diẹ ninu awọn olomi Organic. HEMC le ni tituka ni omi tutu. Idojukọ ti o ga julọ jẹ ipinnu nipasẹ iki nikan. Solubility yatọ pẹlu iki. Isalẹ awọn iki, ti o tobi ni solubility.
2. Iyọ: Awọn ọja HEMC jẹ awọn ethers cellulose ti kii ṣe ionic ati kii ṣe polyelectrolytes, nitorinaa wọn jẹ iduroṣinṣin ni awọn ojutu olomi nigbati awọn iyọ irin tabi awọn elekitiroti Organic wa, ṣugbọn afikun afikun ti awọn elekitiroti le fa gelation ati ojoriro.
3. Iṣẹ ṣiṣe dada: Nitori iṣẹ ṣiṣe dada ti ojutu olomi, o le ṣee lo bi oluranlowo aabo colloidal, emulsifier ati dispersant.
4. Geli gbona: Nigbati ojutu olomi ti awọn ọja HEMC ba gbona si iwọn otutu kan, o di akomo, awọn gels, ati precipitates, ṣugbọn nigbati o ba tutu nigbagbogbo, o pada si ipo ojutu atilẹba, ati iwọn otutu ninu eyiti jeli ati ojoriro yii waye ti wa ni o kun Da lori wọn lubricants, suspending Eedi, aabo colloid, emulsifiers ati be be lo.
5. Metabolism inert ati õrùn kekere ati lofinda: HEMC ti wa ni lilo pupọ ni ounjẹ ati oogun nitori kii yoo jẹ metabolized ati pe o ni oorun kekere ati lofinda.
6. Imuwodu resistance: HEMC ni o ni jo ti o dara imuwodu resistance ati ti o dara iki iduroṣinṣin nigba gun-igba ipamọ.
7. Iduroṣinṣin PH: Itọka ti ojutu olomi ti awọn ọja HEMC ko ni ipa nipasẹ acid tabi alkali, ati pe iye pH jẹ iduroṣinṣin laarin iwọn 3.0 si 11.0.

Ohun elo:

Hydroxyethyl methylcellulose le ṣee lo bi oluranlowo aabo colloidal, emulsifier ati dispersant nitori iṣẹ ṣiṣe-dada rẹ ni ojutu olomi. Awọn apẹẹrẹ ohun elo rẹ jẹ bi atẹle:

1. Ipa ti hydroxyethyl methylcellulose lori iṣẹ simenti. Hydroxyethyl methylcellulose jẹ alainirun, adun, lulú funfun ti kii ṣe majele ti o le tuka ninu omi tutu lati ṣe ojutu viscous ti o han gbangba. O ni awọn abuda ti o nipọn, abuda, pipinka, emulsifying, film-forming, suspending, adsorbing, gelling, dada ti nṣiṣe lọwọ, mimu ọrinrin ati idaabobo colloid. Niwọn igba ti ojutu olomi naa ni iṣẹ ṣiṣe dada, o le ṣee lo bi oluranlowo aabo colloidal, emulsifier ati dispersant. Hydroxyethyl methylcellulose ojutu olomi ni hydrophilicity ti o dara ati pe o jẹ oluranlowo idaduro omi daradara.
2. Awọ iderun pẹlu irọrun giga ti pese, eyiti o jẹ ti awọn ohun elo aise ni awọn apakan nipasẹ iwuwo: 150-200 g ti omi deionized; 60-70 g ti funfun akiriliki emulsion; 550-650 g ti kalisiomu eru; 70-90 g lulú talcum; 30-40g ipilẹ cellulose olomi ojutu; 10-20g lignocellulose olomi ojutu; 4-6g iranlowo fiimu; 1.5-2.5g apakokoro ati bactericide; 1.8-2.2g kaakiri; 3.5-4.5g; Ethylene glycol 9-11g; Awọn ojutu olomi hydroxyethyl methylcellulose ti a ṣe nipasẹ itusilẹ 2-4% hydroxyethyl methylcellulose ninu omi; Ojutu olomi lignocellulose jẹ ti 1-3% Lignocellulose ti a ṣe nipasẹ itusilẹ ninu omi.

Igbaradi:

Ọna igbaradi ti hydroxyethyl methylcellulose, ọna naa ni lati lo owu ti a ti tunṣe bi ohun elo aise ati ohun elo afẹfẹ ethylene gẹgẹbi oluranlowo etherification lati ṣeto hydroxyethyl methylcellulose. Awọn ẹya iwuwo ti awọn ohun elo aise fun igbaradi hydroxyethyl methyl cellulose jẹ bi atẹle: awọn ẹya 700-800 ti toluene ati adalu isopropanol bi epo, awọn ẹya 30-40 ti omi, awọn ẹya 70-80 ti iṣuu soda hydroxide, awọn ẹya 80-85 ti owu ti a ti tunṣe, oruka 20-28 awọn ẹya ara oxyethane, 80-90 awọn ẹya ara ti methyl kiloraidi, 16-19 awọn ẹya ara ti glacial acetic acid; Awọn igbesẹ pataki ni:

Igbesẹ akọkọ, ninu kettle ifaseyin, ṣafikun toluene ati adalu isopropanol, omi, ati iṣuu soda hydroxide, gbona si 60-80 ° C, jẹ ki o gbona fun awọn iṣẹju 20-40;

Igbesẹ keji, alkalization: tutu awọn ohun elo ti o wa loke si 30-50 ° C, fi owu ti a ti tunṣe, fun sokiri toluene ati isopropanol adalu, fifa soke si 0.006Mpa, fọwọsi nitrogen fun awọn iyipada 3, ki o si ṣe lẹhin igbasilẹ Alkalinization, awọn Awọn ipo alkalization jẹ: akoko alkalization jẹ wakati 2, ati iwọn otutu alkalization jẹ 30 ° C si 50 ° C;

Igbesẹ kẹta, etherification: lẹhin ti alkalization ti pari, a ti yọ reactor si 0.05-0.07MPa, ati ethylene oxide ati methyl chloride ti wa ni afikun fun awọn iṣẹju 30-50; ipele akọkọ ti etherification: 40-60 ° C, 1.0-2.0 Wakati, titẹ ni iṣakoso laarin 0.15 ati 0.3Mpa; ipele keji ti etherification: 60～90℃, 2.0～2.5 wakati, titẹ ni iṣakoso laarin 0.4 ati 0.8Mpa;

Igbesẹ kẹrin, didoju: Ṣafikun glacial acetic acid ti a wiwọn ni ilosiwaju si kettle ojoriro, tẹ sinu ohun elo etherified fun didoju, gbe iwọn otutu soke si 75-80 ° C fun ojoriro, iwọn otutu ga si 102 ° C, ati pH. iye jẹ 6 Ni 8 wakati kẹsan, awọn desolventization ti wa ni ti pari; awọn ojò desolventization ti wa ni kún pẹlu tẹ ni kia kia omi itọju nipa a yiyipada osmosis ẹrọ ni 90 ° C to 100 ° C;

Igbesẹ karun, fifọ centrifugal: awọn ohun elo ti o wa ni ipele kẹrin ti wa ni centrifuged nipasẹ kan petele centrifuge skru centrifuge, ati awọn ohun elo ti o yapa ti wa ni ti o ti gbe lọ si kan fifọ ojò kún pẹlu gbona omi ni ilosiwaju fun fifọ awọn ohun elo;

Igbesẹ kẹfa, gbigbẹ centrifugal: ohun elo ti a fọ ​​ni a gbe sinu ẹrọ gbigbẹ nipasẹ centrifuge skru petele, ati pe ohun elo naa ti gbẹ ni 150-170 ° C, ati ohun elo ti o gbẹ ti wa ni fifọ ati akopọ.

Ti a ṣe afiwe pẹlu imọ-ẹrọ iṣelọpọ cellulose ether ti o wa tẹlẹ, kiikan ti o wa lọwọlọwọ nlo ohun elo afẹfẹ ethylene bi oluranlowo etherification lati mura hydroxyethyl methyl cellulose, eyiti o ni agbara anti-mold ti o dara nitori awọn ẹgbẹ hydroxyethyl ti o ni ninu. O ni iduroṣinṣin iki ti o dara ati imuwodu resistance lakoko ibi ipamọ igba pipẹ. O le ṣee lo dipo awọn ethers cellulose miiran.