Focus on Cellulose ethers

Cellulose ether classification hydroxyethyl cellulose le hydroxypropyl methylcellulose

Li-cellulose ethers ke mefuta e fapaneng ea li-polymers tse qhibilihang ka metsing tse tsoang ho selulose, polima ea tlhaho e fumanehang maboteng a lisele tsa semela. Li-ether tsena li na le thepa e ikhethang e kang ho teteka, ho tsitsisa, ho etsa lifilimi, le ho boloka metsi, 'me li sebelisoa haholo liindastering tse sa tšoaneng tse kang meriana, lijo, litlolo le kaho. Har'a li-cellulose ethers, hydroxyethyl cellulose (HEC) le hydroxypropyl methylcellulose (HPMC) ke lintho tse peli tsa bohlokoa tse nkiloeng, e 'ngoe le e' ngoe e na le thepa le lisebelisoa tse fapaneng.

1. Kenyelletso ea li-cellulose ethers

A. Sebopeho sa Cellulose le Litlhahiso

Kakaretso ea cellulose:

Cellulose ke polymer e nang le linear e entsoeng ka likaroloana tsa tsoekere tse hokahantsoeng ke libonto tsa β-1,4-glycosidic.

E ruile ka marako a lisele tsa limela 'me e fana ka ts'ehetso ea sebopeho le ho tiea ho limela tsa limela.

Lintho tse tsoang ho cellulose ether:

Li-cellulose ethers li tsoa ho selulose ka phetoho ea lik'hemik'hale.

Li-Ether li hlahisoa ho eketsa solubility le ho fetola thepa ea ts'ebetso.

2. Hydroxyethylcellulose (HEC)

A. Sebopeho le motsoako

Sebopeho sa lik'hemik'hale:

HEC e fumanoa ka etherification ea cellulose e nang le ethylene oxide.

Lihlopha tsa Hydroxyethyl li nka sebaka sa lihlopha tsa hydroxyl ka sebopeho sa cellulose.

Degree of substitution (DS):

DS e bolela palo e tloaelehileng ea lihlopha tsa hydroxyethyl ka unit ea anhydroglucose.

E ama solubility, viscosity le thepa e meng ea HEC.

B. Tlhaho

Sollubility:

HEC e qhibiliha ka metsing a batang le a chesang, e fana ka phetoho ea kopo.

Viscosity:

Joaloka rheology modifier, e ama botenya le phallo ea tharollo.

E fapana ho ea ka DS, mahloriso le mocheso.

Moetso oa lifilimi:

E etsa filimi e hlakileng e nang le sekhomaretsi se setle haholo.

C. Kopo

lithethefatsi:

E sebelisoa e le motenya ka mefuta ea litekanyetso tsa metsi.

Ntlafatsa viscosity le botsitso ba marotholi a mahlo.

Lipente le Liaparo:

E ntlafatsa viscosity mme e fana ka thepa e ntle haholo ea botenya.

Ntlafatsa ho khomarela pente le botsitso.

Lihlahisoa tsa tlhokomelo ea motho ka mong:

E fumaneha ka har'a li-shampoo, litlolo le litlolo e le setepi le se tsitsitseng.

E fana ka sebopeho se boreleli ho litlolo.

3. Hydroxypropylmethylcellulose (HPMC)

A. Sebopeho le motsoako

Sebopeho sa lik'hemik'hale:

HPMC e entsoe ka ho nkela lihlopha tsa hydroxyl sebaka ka lihlopha tsa methoxy le hydroxypropyl.

Etherification e etsahala ka karabelo ea propylene oxide le methyl chloride.

Methoxy le hydroxypropyl:

 

Sehlopha sa methoxy se kenya letsoho ho solubility, ha sehlopha sa hydroxypropyl se ama viscosity.

B. Tlhaho

Thermal gelation:

E bonts'a gelation e fetohang ea mocheso, e etsa li-gel ka mocheso o phahameng.

E ka sebelisoa bakeng sa litokisetso tsa meriana tse laoloang.

Ho boloka metsi:

Bokhoni bo botle ba ho boloka metsi, bo etsang hore bo lokele lits'ebetso tsa kaho.

Ts'ebetso ea bokaholimo:

E bonts'a lintho tse kang surfactant ho thusa ho tsitsisa li-emulsion.

C. Kopo

Indasteri ea kaho:

E sebelisoa joalo ka se bolokang metsi seretseng se entsoeng ka samente.

E ntlafatsa ho sebetsa le ho khomarela li-adhesive tsa lithaele.

lithethefatsi:

E sebelisoa ka tloaelo ho litokisetso tsa meriana ea molomo le ea lihlooho.

E thusa ho lokolloa ha lithethefatsi tse laoloang ka lebaka la bokhoni ba eona ba ho etsa li-gel.

indasteri ea lijo:

E sebetsa joalo ka motenya le ho tsitsisa lijong.

E fana ka sebopeho se ntlafalitsoeng le molomo lits'ebetsong tse itseng.

4. Tlhahlobo ea papiso

A. Phapang ka ho kopanya

HEC le HPMC synthesis:

HEC e hlahisoa ka ho arabela selulose ka ethylene oxide.

HPMC synthesis e kenyelletsa phetisetso e habeli ea lihlopha tsa methoxy le hydroxypropyl.

B. Liphapang tsa tšebetso

Solubility le Viscosity:

HEC e qhibiliha metsing a batang le a chesang, ha ho qhibiliha ha HPMC ho angoa ke litaba tsa sehlopha sa methoxy.

HEC ka kakaretso e bonts'a viscosity e tlase ha e bapisoa le HPMC.

Boitšoaro ba li-gel:

Ho fapana le HPMC, e etsang li-gel tse fetolehang, HEC ha e kene ka mocheso oa mocheso.

C. Liphapang tsa tšebeliso

Ho boloka metsi:

HPMC e ratoa bakeng sa lits'ebetso tsa kaho ka lebaka la thepa ea eona e ntle ea ho boloka metsi.

Bokhoni ba ho etsa lifilimi:

HEC e etsa lifilimi tse hlakileng ka ho khomarela hantle, ho etsa hore e tšoanelehe bakeng sa likopo tse itseng moo ho thehoa ha filimi ho leng bohlokoa.

5 Qetello

Ka bokhutšoanyane, hydroxyethyl cellulose (HEC) le hydroxypropyl methylcellulose (HPMC) ke li-cellulose ethers tsa bohlokoa tse nang le thepa le lisebelisoa tse ikhethang. Mehaho ea tsona e ikhethang ea lik'hemik'hale, mekhoa ea ho kopanya, le thepa ea ts'ebetso e etsa hore li sebetse ka bongata liindastering tse fapaneng. Ho utloisisa phapang pakeng tsa HEC le HPMC ho ka u thusa ho etsa qeto e nang le tsebo ha u khetha ether ea cellulose e nepahetseng bakeng sa kopo e itseng, ebang ke meriana, kaho, lipente kapa lihlahisoa tsa tlhokomelo ea botho. Ha thekenoloji e ntse e tsoela pele ka saense, lipatlisiso tse ling li ka senola lits'ebetso le liphetoho tse ngata, ka hona tsa ntlafatsa ts'ebeliso ea li-cellulose ethers tsena mafapheng a fapaneng.


Nako ea poso: Dec-11-2023
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