Tsepamisa maikutlo ho Cellulose ethers

Hydroxypropylcellulose e etsoa joang?

Hydroxypropylcellulose (HEC) e tsoa ho cellulose, polymer ea tlhaho e fumanehang maboteng a lisele tsa semela. HPC e sebelisoa haholo liindastering tse fapaneng tse kang tsa meriana, litlolo le liindasteri tsa lijo ka lebaka la thepa ea eona e ntle ea ho etsa lifilimi le ho tenya. Tlhahiso ea hydroxypropylcellulose e kenyelletsa mehato e mengata mme ts'ebetso e ka ba e rarahaneng.

Selelekela sa hydroxypropylcellulose:

1. Ho sebelisa cellulose e le lisebelisoa tsa ho qala:

Mehloli e ka sehloohong ea selulose ke lisebelisoa tsa semela tse kang makhasi a lehong kapa k'hothone. Cellulose ke polymer e nang le linear e entsoeng ka likaroloana tsa tsoekere tse hokahantsoeng ke libonto tsa β-1,4-glycosidic. E na le boemo bo phahameng ba polymerization, ka likete tsa likarolo tsa tsoekere tse etsang liketane tse telele.

2. Maikutlo a Etherification:

Tšimoloho ea hydroxypropylcellulose e kenyelletsa ho kenngoa ha lihlopha tsa hydroxypropyl mokokotlong oa cellulose ka etherification. Karabelo ena hangata e kenyelletsa tšebeliso ea propylene oxide e le alkylating agent.

Cellulose + propylene oxide → alkali-catalyzed hydroxypropyl cellulose + by-product cellulose + propylene oxide alkali-catalyzed hydroxypropyl cellulose + by-product

Base catalysis e bohlokoa ho khothaletsa karabelo lipakeng tsa lihlopha tsa cellulose hydroxyl le propylene oxide. Hangata mohato ona o etsoa tlas'a maemo a laoloang ho netefatsa tekanyo e lakatsehang ea ho fetola (DS) ea lihlopha tsa hydroxypropyl ka ketane ea cellulose.

3. Hydroxypropylation:

Hydroxypropylation e kenyelletsa ho kenyelletsoa ha lihlopha tsa hydroxypropyl mokokotlong oa cellulose. Phetoho ena e fana ka ho qhibiliha ho ntlafalitsoeng le lisebelisoa tse ling tse lakatsehang ho cellulosic polymer. Maemo a ho itšoara, ho kenyelletsa mocheso, khatello le nako ea ho itšoara, li laoloa ka hloko ho finyella thepa e lakatsehang ea sehlahisoa.

4. Kalafo ea alkali:

Ka mor'a hydroxypropylation, phekolo ea alkaline hangata e sebelisoa ho fokotsa litšila leha e le life tse setseng tsa asiti le ho fetola pH ea motsoako oa karabelo. Mohato ona ke oa bohlokoa bakeng sa ts'ebetso e latelang ea tlhoekiso.

5. Mehato ea tlhoekiso:

Ka mor'a karabelo ea etherification, mehato e 'maloa ea tlhoekiso e atisa ho etsoa ho fumana high-purity hydroxypropylcellulose. Mehato ena e ka kenyelletsa:

Hlatsoa: Hlatsoa motsoako oa karabelo ho tlosa li-reagents tse setseng, lihlahisoa le selulose e sa sebetsanoang.

Filtration: Filtration e sebelisoa ho arola litšila tse tiileng le motsoako oa karabelo.

Ho omisa: Selulose e metsi ea hydroxypropyl e ntan'o omisoa ho tlosa mongobo ofe kapa ofe o setseng.

6. Taolo ea boima ba limolek'hule:

Boima ba limolek'hule tsa hydroxypropylcellulose bo ka laoloa nakong ea synthesis ho etsa hore thepa ea eona e lumellane le lits'ebetso tse ikhethileng. Sena se finyelloa ka ho lokisa maemo a karabelo, joalo ka bongata ba li-reagents le nako ea karabelo.

Tlhahiso ea indasteri:

1. Ts'ebetso ea nakoana kapa e tsoelang pele:

Tlhahiso ea selulose ea hydroxypropyl e ka etsoa ka batch kapa mekhoa e tsoelang pele. Ts'ebetso ea li-batch e loketse tlhahiso e nyenyane, ha ts'ebetso e tsoelang pele e loketse haholoanyane bakeng sa tlhahiso e kholo.

2. Taolo ea boleng:

Mehato ea taolo ea boleng e kengoa ts'ebetsong mekhahlelong eohle ea ts'ebetso ea tlhahiso ho netefatsa botsitso le bohloeki ba sehlahisoa sa ho qetela. Mekhoa ea ho hlahloba e kang chromatography, spectroscopy le lithuto tsa rheological li sebelisoa ho hlahloba lintlha tsa bohlokoa tse kang tekanyo ea ho fetola, boima ba limolek'hule le bohloeki.

Lisebelisoa tsa Hydroxypropyl Cellulose:

1. Indasteri ea meriana:

Hydroxypropylcellulose e sebelisoa haholo litokisetsong tsa meriana e le ntho e tlamang, e senyang le e laoloang ea tokollo. Ho lumellana ha eona le mefuta e mengata ea lithethefatsi le ho se sebetse ha eona ho etsa hore e be mothusi ea fapaneng.

2. Indasteri ea litlolo:

Ka indasteri ea litlolo, hydroxypropylcellulose e sebelisoa ha ho etsoa lihlahisoa tsa tlhokomelo ea moriri, litlolo tsa letlalo le lihlahisoa tse ling tsa tlhokomelo ea motho. Lintho tsa eona tsa ho etsa lifilimi li etsa hore e be ea bohlokoa lihlahisoa tsa tlhokomelo ea moriri.

3. Indasteri ea lijo:

Indastering ea lijo, hydroxypropylcellulose e sebelisoa e le ntho e teteaneng le ea gelling. E fumanoa lijong tse sa tšoaneng 'me e thusa ho ntlafatsa sebopeho sa bona le botsitso.

Tšimoloho ea hydroxypropylcellulose e kenyelletsa etherification ea selulose ka ho eketsoa ha lihlopha tsa hydroxypropyl. Karabelo hangata e hlahisoa ke motheo, e lateloa ke mehato ea tlhoekiso ho fumana sehlahisoa se hloekileng haholo. Tlhahiso ea indasteri e ka etsoa ka batch kapa mekhoa e tsoelang pele ka mehato e tiileng ea ho laola boleng. Hydroxypropylcellulose e na le mefuta e mengata ea lisebelisoa indastering ea meriana, ea litlolo le ea lijo ka lebaka la thepa ea eona e ikhethang le ho feto-fetoha ha maemo. Ntlafatso e tsoelang pele ea lits'ebetso tsa tlhahiso le nts'etsopele ea lits'ebetso tse ncha li totobatsa


Nako ea poso: Dec-26-2023
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