Ho lokisoa ha hydroxyethyl cellulose

Hydroxyethyl cellulose (HEC) ke polymer e seng ionic, e qhibilihang ka metsing e nkiloeng ho cellulose, polymer ea tlhaho e fumanoang maboteng a sele ea limela. E sebelisoa haholo liindastering tse fapaneng, ho kenyeletsoa meriana, litlolo, lipente le likhomaretsi, ka lebaka la thepa ea eona e ntle ea ho teteana, ho etsa filimi le ea rheological. Ho lokisoa ha hydroxyethyl cellulose ho kenyelletsa ho etherification ea cellulose ka ethylene oxide tlas'a maemo a alkaline. Ts'ebetso ena e ka aroloa ka mehato e 'maloa ea bohlokoa: tlhoekiso ea cellulose, alkalization, etherification, neutralization, ho hlatsoa le ho omisa.

1. Tlhoekiso ea Cellulose
Mohato oa pele oa ho lokisa hydroxyethyl cellulose ke ho hloekisa cellulose, eo hangata e fumanoang ho tsoa ho pulp ea lehong kapa linter tsa k'hothone. Cellulose e tala e na le litšila tse kang lignin, hemicellulose, le lintho tse ling tse ntšoang tse lokelang ho tlosoa ho fumana cellulose e hloekileng haholo e loketseng phetoho ea lik'hemik'hale.

Mehato e amehang:

Ho Sebetsa ka Mechine: Cellulose e tala e sebetsoa ka mechine ho fokotsa boholo ba eona le ho eketsa sebaka sa eona sa bokaholimo, e leng se thusang kalafo ea lik'hemik'hale e latelang.
Kalafo ea Lik'hemik'hale: Cellulose e phekoloa ka lik'hemik'hale tse kang sodium hydroxide (NaOH) le sodium sulfite (Na2SO3) ho qhaqha lignin le hemicellulose, e lateloe ke ho hlatsoa le ho soeufatsa ho tlosa litšila tse setseng le ho fumana cellulose e tšoeu, e nang le likhoele.

2. Alkalization
Selulose e hloekisitsoeng e ntan'o ba alkalized ho e kenya tshebetsong bakeng sa karabelo ya etherification. Sena se kenyeletsa ho phekola selulose ka tharollo ya metsi ya sodium hydroxide.

Karabelo:
Selulose+NaOH→Selulose ea alkali

Mokhoa:

Selulose e leketlile ka metsing, 'me tharollo ea sodium hydroxide ea eketsoa. ​​Khakanyo ea NaOH hangata e tloha ho 10-30%, 'me karabelo e etsoa mochesong o pakeng tsa 20-40°C.
Motsoako o hlohlelletsoa ho netefatsa hore alkali e monyela ka ho lekana, e leng se lebisang ho thehoeng ha alkali cellulose. Karolo ena e mahareng e arabela haholoanyane ho ethylene oxide, e leng se nolofalletsang ts'ebetso ea etherification.

3. Ho fetola 'mala oa ether
Mohato oa bohlokoa oa ho lokisa hydroxyethyl cellulose ke ho etherization ea alkali cellulose ka ethylene oxide. Karabelo ena e hlahisa lihlopha tsa hydroxyethyl (-CH2CH2OH) mokokotlong oa cellulose, e leng se etsang hore e qhibilihe ka metsing.

Karabelo:
Alkali cellulose+Ethylene oxide→Hydroxyethyl cellulose+NaOH

Mokhoa:

Ethylene oxide e eketsoa ho alkali cellulose, ebang ke ka sehlopha kapa ka ts'ebetso e tsoelang pele. Karabelo hangata e etsoa ka autoclave kapa pressure reactor.
Maemo a karabelo, ho kenyeletsoa mocheso (50-100°C) le khatello (1-5 atm), a laolwa ka hloko ho netefatsa hore ho nkeloa sebaka ha lihlopha tsa hydroxyethyl ho nepahetse. Tekanyo ea ho nkeloa sebaka (DS) le ho nkeloa sebaka ha molar (MS) ke liparamente tsa bohlokoa tse susumetsang litšobotsi tsa sehlahisoa sa ho qetela.

4. Ho se nke lehlakore
Kamora karabelo ea etherification, motsoako o na le hydroxyethyl cellulose le sodium hydroxide e setseng. Mohato o latelang ke neutralization, moo alkali e feteletseng e fokotsoang ka ho sebelisa asiti, eo hangata e leng acetic acid (CH3COOH) kapa hydrochloric acid (HCl).

Karabelo:NaOH+HCl→NaCl+H2O

Mokhoa:

Asiti e eketsoa butle-butle motswakong wa karabelo tlasa maemo a laolwang ho qoba mocheso o feteletseng le ho thibela ho senyeha ha hydroxyethyl cellulose.
Motswako o sa koaheloang o fetoloa pH ho netefatsa hore o ka har'a tekanyo e lakatsehang, hangata o le haufi le pH e sa koaheloang (6-8).
5. Ho hlatsoa
Kamora ho hlatsuoa, sehlahisoa se lokela ho hlatsuoa ho tlosa letsoai le lihlahisoa tse ling tse setseng. Mohato ona ke oa bohlokoa bakeng sa ho fumana cellulose e hloekileng ea hydroxyethyl.

Mokhoa:

Motswako wa karabelo o hlapollwa ka metsi, mme hydroxyethyl cellulose e arolwa ka ho sefa kapa ho centrifugation.
Selulose e arohaneng ea hydroxyethyl e hlatsuoa khafetsa ka metsi a hloekisitsoeng ho tlosa matsoai le litšila tse setseng. Ts'ebetso ea ho hlatsoa e tsoela pele ho fihlela metsi a hlatsoang a fihla boemong bo itseng ba ho tsamaisa metsi, e leng se bontšang ho tlosoa ha litšila tse qhibilihang.
6. Ho omisa
Mohato oa ho qetela oa ho lokisa hydroxyethyl cellulose ke ho omisa. Mohato ona o tlosa metsi a mangata, o etsa hore sehlahisoa se omileng, se phofshoana se lokele lits'ebetso tse fapaneng.

Mokhoa:

Selulose ea hydroxyethyl e hlatsoitsoeng e hasoa holim'a literei tsa ho omisa kapa e fetisoa ka kotopo ea ho omisa. Mocheso oa ho omisa o laoloa ka hloko ho qoba ho senyeha ha mocheso, hangata ho tloha ho 50-80°C.
Ka tsela e 'ngoe, ho omisa ka spray ho ka sebelisoa bakeng sa ho omisa ka potlako le ka katleho. Ha ho omisoa ka spray, tharollo ea metsi ea hydroxyethyl cellulose e fetoloa marotholi a masesaane ebe e omisoa ka har'a molapo o chesang oa moea, e leng se fellang ka phofo e ntle.
Sehlahisoa se omisitsweng se silwa ho fihlela boholo ba dikarolwana tse lakatsehang mme se pakwa bakeng sa polokelo le kabo.
Taolo ea Boleng le Litšebeliso
Nakong eohle ea ts'ebetso ea ho lokisa, mehato e matla ea taolo ea boleng e kenngoa tšebetsong ho netefatsa botsitso le boleng ba hydroxyethyl cellulose. Litekanyetso tsa bohlokoa tse kang ho teteana, tekanyo ea ho nkeloa sebaka, mongobo le boholo ba likaroloana li lula li hlahlojoa.

Likopo:

Meriana: E sebelisoa e le sesebelisoa sa ho tiisa, ho kopanya le ho tsitsisa lintho tse kang matlapa, li-suspension le mafura.
Litlolo: E fana ka ho hlaka le sebopeho ho lihlahisoa tse kang litlolo, litlolo le li-shampoo.
Pente le Lipente: E sebetsa e le sesebelisoa sa ho teteana le ho fetola rheology, e ntlafatsa litšobotsi tsa ts'ebeliso le botsitso ba pente.
Indasteri ea Lijo: E sebetsa e le setefatsi, se tsitsisang, le se kopanyang lihlahisoa tse fapaneng tsa lijo.

Ho lokisoa ha hydroxyethyl cellulose ho kenyelletsa letoto la lits'ebetso tse hlalositsoeng hantle tsa lik'hemik'hale le tsa mechini tse reretsoeng ho fetola cellulose ho hlahisa lihlopha tsa hydroxyethyl. Mohato o mong le o mong, ho tloha tlhoekisong ea cellulose ho isa ho omiseng, ke oa bohlokoa ho fumaneng boleng le ts'ebetso ea sehlahisoa sa ho qetela. Thepa e feto-fetohang ea hydroxyethyl cellulose e etsa hore e be motsoako oa bohlokoa liindastering tse ngata, e totobatsa bohlokoa ba mekhoa e nepahetseng ea tlhahiso ho fihlela litlhoko tse ikhethileng tsa lits'ebetso tse fapaneng.