Phetoho ea cellulose etherification

01. Kenyelletso ea cellulose

Cellulose ke macromolecular polysaccharide e entsoeng ka tsoekere. Ha e kenelle ka har'a metsi le lihlapolli tse akaretsang tsa tlhaho. Ke karolo ea mantlha ea lerako la lisele tsa semela, hape ke eona polysaccharide e ajoang ka ho fetesisa le e ngata ka ho fetisisa tlhahong.

Cellulose ke mohloli o mongata o ka nchafatsoang ka ho fetesisa lefatšeng, hape ke polymer ea tlhaho e nang le pokello e kholo ka ho fetisisa. E na le melemo ea hore e ka nchafatsoa, ​​e ka senyeha ka botlalo, le ho lumellana hantle ha lintho.

02. Mabaka a ho fetola selulose

Li-macromolecules tsa cellulose li na le palo e kholo ea lihlopha tsa -OH. Ka lebaka la phello ea li-hydrogen bond, matla a pakeng tsa macromolecules a batla a le maholo, a tla lebisa ho enthalpy e kholo ea ho qhibiliha △H; ka lehlakoreng le leng, ho na le masale a cellulose macromolecules. Joalo ka sebopeho, ho tiea ha ketane ea limolek'hule ho hoholo, ho tla lebisa phetohong e nyane ea melting entropy ΔS. Mabaka ana a mabeli a etsa hore mocheso oa selulose e qhibilihisitsoeng (= △H / △S ) e be holimo, 'me mocheso oa ho bola oa selulose o batla o le tlaase. Ka hona, ha selulose e futhumetse mocheso o itseng, likhoele li tla hlaha Ketsahalo ea hore selulose e se e senyehile pele e qala ho qhibiliha, ka hona, ho sebetsa ha thepa ea selulose ho ke ke ha e-ba le mokhoa oa ho qala ho qhibiliha ebe o bopa.

03. Bohlokoa ba phetoho ea cellulose

Ka ho fokotseha butle-butle ha mehloli ea mesaletsa ea lintho tsa khale le mathata a tebileng a tikoloho a ntseng a eketseha a bakoang ke litšila tsa masela a fiber a lik'hemik'hale, nts'etsopele le ts'ebeliso ea thepa ea tlhaho e nchafalitsoeng e fetohile e 'ngoe ea libaka tse chesang tseo batho ba li elang hloko. Cellulose ke mohloli o mongata oa tlhaho o ka nchafatsoang ka ho fetisisa tlhahong. E na le thepa e ntle joalo ka hygroscopicity e ntle, antistatic, moea o kenang ka matla, ho daea hantle, ho apara hantle, ho sebetsa ha masela ha bonolo, le biodegradability. E na le litšobotsi tse ke keng tsa bapisoa le likhoele tsa lik'hemik'hale. .

Limolek'hule tsa cellulose li na le palo e kholo ea lihlopha tsa hydroxyl, tse bonolo ho theha maqhama a hydrogen a intramolecular le intermolecular, 'me a bola ka mocheso o phahameng ntle le ho qhibiliha. Leha ho le joalo, cellulose e na le reactivity e ntle, 'me bond ea eona ea hydrogen e ka senngoa ke phetoho ea lik'hemik'hale kapa karabelo ea grafting, e ka fokotsang ntlha ea ho qhibiliha ka katleho. Joalo ka lihlahisoa tse fapaneng tsa indasteri, e sebelisoa haholo ho masela, karohano ea lera, polasetiki, koae le likobo.

04. Phetoho ea cellulose etherification

Cellulose ether ke mofuta o tsoang ho cellulose o fumanoang ka ho fetola etherification ea selulose. E sebelisoa haholo ka lebaka la botenya ba eona bo botle, emulsification, ho emisoa, sebopeho sa filimi, colloid e sireletsang, ho boloka mongobo le thepa ea ho khomarela. E sebelisoa lijong, meriana, ho etsa pampiri, ho penta, thepa ea mohaho, joalo-joalo.

Etherification ea cellulose ke letoto la li-derivatives tse hlahisoang ke karabelo ea lihlopha tsa hydroxyl ka ketane ea molek'hule ea cellulose e nang le li-alkylating agents tlas'a maemo a alkaline. Tšebeliso ea lihlopha tsa hydroxyl e fokotsa palo ea li-intermolecular hydrogen bonds ho fokotsa matla a intermolecular, ka tsela eo ho Ntlafatsa botsitso ba mocheso oa selulose, ho ntlafatsa ts'ebetso ea ts'ebetso ea thepa, 'me ka nako e ts'oanang ho fokotsa ntlha ea ho qhibiliha ea selulose.

Mehlala ea litlamorao tsa phetoho ea etherification mesebetsing e meng ea selulose:

Ba sebelisa k'hothone e hloekisitsoeng e le thepa ea motheo e tala, bafuputsi ba ile ba sebelisa mohato o le mong oa etherification ho lokisetsa carboxymethyl hydroxypropyl cellulose complex ether e nang le karabelo e tšoanang, viscosity e phahameng, ho hanyetsa acid e ntle le ho hanyetsa letsoai ka alkalization le etherification reactions. Ho sebelisa mohato o le mong oa etherification, carboxymethyl hydroxypropyl cellulose e na le khanyetso e ntle ea letsoai, ho hanyetsa acid le ho qhibiliha. Ka ho fetola litekanyo tse lekanyelitsoeng tsa propylene oxide le chloroacetic acid, lihlahisoa tse nang le likarolo tse fapaneng tsa carboxymethyl le hydroxypropyl li ka lokisoa. Liphetho tsa liteko li bonts'a hore carboxymethyl hydroxypropyl cellulose e hlahisoang ke mokhoa oa mohato o le mong e na le potoloho e khuts'oane ea tlhahiso, tšebeliso e tlase ea solvent, mme sehlahisoa se na le khanyetso e ntle ho matsoai a mononovalent le divalent le ho hanyetsa acid e ntle.

05. Tebello ea phetoho ea cellulose etherification

Cellulose ke lisebelisoa tsa bohlokoa tsa lik'hemik'hale le lik'hemik'hale tse nang le lisebelisoa tse ngata, tse tala le tse nang le tikoloho, 'me li ka nchafatsoa. Litholoana tsa phetoho ea cellulose etherification li na le ts'ebetso e babatsehang, mefuta e mengata ea tšebeliso le liphello tse babatsehang tsa tšebeliso, 'me li finyella litlhoko tsa moruo oa naha ka tekanyo e kholo. 'Me litlhoko tsa nts'etsopele ea sechaba, ka tsoelo-pele e tsoelang pele ea thekenoloji le ho phethahala ha khoebo nakong e tlang, haeba lisebelisoa tsa maiketsetso le mekhoa ea maiketsetso ea lihlahisoa tsa cellulose li ka ntlafatsoa haholoanyane, li tla sebelisoa ka botlalo le ho hlokomela mefuta e mengata ea likopo. . Boleng