Phetoho ea etherification ea cellulose

01. Selelesa sa selelulose

Cellulose ke polysaccharide e kholo e entsoeng ka glucose. Ha e qhibilihe metsing le li-solvents tse akaretsang tsa lintho tse phelang. Ke karolo e ka sehloohong ea lerako la sele ea limela, 'me hape ke polysaccharide e ajoang haholo le e ngata ka ho fetisisa tlhahong.

Cellulose ke mohloli o moholo ka ho fetisisa o ka ntjhafatswang lefatšeng, hape ke polymer ya tlhaho e nang le pokello e kgolo ka ho fetisisa. E na le melemo ya ho ntjhafatswa, ho bola ka ho feletseng, le ho tsamaisana hantle le dintho tse phelang.

02. Mabaka a ho fetola cellulose

Li-macromolecule tsa cellulose li na le palo e kholo ea lihlopha tsa -OH. Ka lebaka la phello ea litlamo tsa haedrojene, matla a pakeng tsa li-macromolecule a maholo haholo, e leng se tla lebisa ho enthalpy e kholo e qhibilihang △H; ka lehlakoreng le leng, ho na le masale ka har'a li-macromolecule tsa cellulose. Joalo ka sebopeho, ho tiea ha ketane ea limolek'hule ho hoholo, e leng se tla lebisa phetohong e nyane ea entropy e qhibilihang ΔS. Mabaka ana a mabeli a etsa hore mocheso oa cellulose e qhibilihisitsoeng (= △H / △S ) o be holimo, 'me mocheso oa ho bola ha cellulose o be tlase haholo. Ka hona, ha cellulose e futhumatsoa mochesong o itseng, likhoele li tla hlaha. Ketsahalo ea hore cellulose e se e bolile pele e qala ho qhibiliha, ka hona, ts'ebetso ea thepa ea cellulose e ke ke ea amohela mokhoa oa ho qhibiliha pele ebe e etsoa.

03. Bohlokoa ba phetoho ea cellulose

Ka ho fokotseha butle-butle ha mehlodi ya mesaletsa ya kgale le mathata a tebileng a tikoloho a bakwang ke masela a dikhemikhale tsa dikhemikhale, ntshetsopele le tshebediso ya thepa ya tlhaho ya dikhemikhale tse ntjhafatswang e se e le e nngwe ya dibaka tse chesang tseo batho ba di elang hloko. Cellulose ke mohlodi wa tlhaho o ntjhafatswang o fumanehang ka bongata ka ho fetisisa tlhahong. E na le thepa e ntle haholo e kang hygroscopicity e ntle, antistatic, air permeability e matla, dae e ntle, ho aparwa ka boiketlo, ho sebetsa ha masela habonolo, le ho bola ha dibopeho. E na le dibopeho tse ke keng tsa bapiswa le dikhoele tsa dikhemikhale.

Limolek'hule tsa selulose li na le palo e kholo ea lihlopha tsa hydroxyl, tse bonolo ho theha maqhama a haedrojene a ka hare ho limolek'hule le a lipakeng tsa limolek'hule, 'me lia bola mochesong o phahameng ntle le ho qhibiliha. Leha ho le joalo, cellulose e na le reactivity e ntle, 'me maqhama a eona a haedrojene a ka senngoa ke phetoho ea lik'hemik'hale kapa karabelo ea grafting, e ka fokotsang ntlha ea ho qhibiliha ka katleho. Jwalo ka mefuta e fapaneng ea lihlahisoa tsa indasteri, e sebelisoa haholo masela, karohano ea lera, polasetiki, koae le lipente.

04. Phetoho ea etherification ea cellulose

Cellulose ether ke mofuta oa setlolo se nkiloeng ke cellulose se fumanoang ka ho fetola etherification ea cellulose. E sebelisoa haholo ka lebaka la ho teteana ha eona hantle, emulsification, suspension, ho thehoa ha filimi, colloid e sireletsang, ho boloka mongobo le thepa ea ho khomarela. E sebelisoa lijong, merianeng, ho etsa pampiri, penteng, thepa ea kaho, jj.

Ho etherification ea cellulose ke letoto la lintho tse hlahisoang ke karabelo ea lihlopha tsa hydroxyl ketane ea limolek'hule tsa cellulose tse nang le li-alkylating agents tlas'a maemo a alkaline. Tšebeliso ea lihlopha tsa hydroxyl e fokotsa palo ea likhokahano tsa hydrogen tsa limolek'hule ho fokotsa matla a limolek'hule, ka hona e ntlafatsa botsitso ba mocheso ba cellulose, e ntlafatsa ts'ebetso ea ts'ebetso ea thepa, 'me ka nako e ts'oanang e fokotsa ntlha ea ho qhibiliha ha cellulose.

Mehlala ea liphello tsa phetoho ea etherification mesebetsing e meng ea cellulose:

Ba sebelisa k'hothone e hloekisitsoeng e le thepa ea motheo e tala, bafuputsi ba sebelisitse mokhoa oa ho etsa etherification oa mohato o le mong ho lokisa ether e rarahaneng ea carboxymethyl hydroxypropyl cellulose e nang le karabelo e ts'oanang, viscosity e phahameng, khanyetso e ntle ea asiti le khanyetso ea letsoai ka alkalization le etherification. Ba sebelisa mokhoa oa ho etsa etherification oa mohato o le mong, carboxymethyl hydroxypropyl cellulose e hlahisoang e na le khanyetso e ntle ea letsoai, khanyetso ea asiti le ho qhibiliha ha asiti. Ka ho fetola bongata bo lekanyelitsoeng ba propylene oxide le chloroacetic acid, lihlahisoa tse nang le likahare tse fapaneng tsa carboxymethyl le hydroxypropyl li ka lokisoa. Liphetho tsa liteko li bontša 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, 'me sehlahisoa se na le khanyetso e ntle ho letsoai la monovalent le divalent le khanyetso e ntle ea asiti.

05. Tebello ea phetoho ea etherification ea cellulose

Cellulose ke thepa ea bohlokoa ea lik'hemik'hale le lik'hemik'hale e nang le mehloli e mengata, e tala ebile e mosa tikolohong, 'me e ka nchafatsoa. ​​Lihlahisoa tsa phetoho ea etherification ea cellulose li na le ts'ebetso e ntle haholo, mefuta e mengata ea ts'ebeliso le litlamorao tse ntle tsa ts'ebeliso, 'me li fihlela litlhoko tsa moruo oa naha ka tekanyo e kholo. 'Me litlhoko tsa nts'etsopele ea sechaba, ka tsoelo-pele e tsoelang pele ea theknoloji le ho phethahala ha khoebo nakong e tlang, haeba lisebelisoa tse tala tsa maiketsetso le mekhoa ea maiketsetso ea lihlahisoa tsa cellulose li ka ntlafatsoa haholoanyane indastering, li tla sebelisoa ka botlalo haholoanyane 'me li phethahatse mefuta e mengata ea lits'ebetso.