Cellulose ether ke tlatsetso ea bohlokoa ea thepa ea moaho, e sebelisoang haholo ho aha seretse, putty phofo, ho roala le lihlahisoa tse ling ho ntlafatsa thepa ea 'mele le ts'ebetso ea kaho ea thepa. Likarolo tse ka sehloohong tsa cellulose ether li kenyelletsa sebopeho sa motheo sa cellulose le li-substituent tse hlahisoang ke phetoho ea lik'hemik'hale, tse fanang ka ho qhibiliha ho ikhethang, ho teteaneng, ho boloka metsi le thepa ea rheological.
1. Sebopeho sa motheo sa cellulose
Cellulose ke e 'ngoe ea li-polysaccharides tse tloaelehileng ka tlhaho, haholo-holo tse nkiloeng ho likhoele tsa limela. Ke karolo ea mantlha ea cellulose ether mme e etsa qeto ea sebopeho sa eona sa mantlha le thepa. Limolek'hule tsa cellulose li entsoe ka li-unit tsa tsoekere tse hokahantsoeng ke β-1,4-glycosidic bond ho etsa sebopeho sa ketane e telele. Sebopeho sena sa linear se fana ka selulose matla a phahameng le boima bo phahameng ba limolek'hule, empa ho qhibiliha ha eona metsing ho fokola. E le ho ntlafatsa ho qhibiliha ha metsi ka selulose le ho ikamahanya le litlhoko tsa thepa ea mohaho, cellulose e hloka ho fetoloa lik'hemik'hale.
2. Likaroloana tsa bohlokoa tsa karabelo ea etherification
Lintho tse ikhethang tsa cellulose ether li finyelloa haholo-holo ke li-substituent tse hlahisoang ke karabelo ea etherification pakeng tsa sehlopha sa hydroxyl (-OH) ea selulose le metsoako ea ether. Li-substitute tse tloaelehileng li kenyelletsa methoxy (-OCH₃), ethoxy (-OC₂H₅) le hydroxypropyl (-CH₂CHOHCH₃). Kenyelletso ea li-substitute tsena e fetola ho qhibiliha, ho teteana le ho boloka metsi a selulose. Ho latela li-substituent tse fapaneng tse hlahisitsoeng, li-cellulose ethers li ka aroloa ka methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl methyl cellulose (HPMC) le mefuta e meng.
Methyl cellulose (MC): Methyl cellulose e thehoa ka ho hlahisa li-methyl substituents (-OCH₃) ka har'a lihlopha tsa hydroxyl ka molek'hule ea cellulose. Ether ena ea cellulose e na le matla a ho qhibiliha ha metsi le thepa e teteaneng 'me e sebelisoa haholo ka seretse se omeletseng, sekhomaretsi le liphahlo. MC e na le ts'ebetso e ntle ea ho boloka metsi mme e thusa ho fokotsa tahlehelo ea metsi ho thepa ea kaho, ho netefatsa ho khomarela le matla a seretse le putty powder.
Hydroxyethyl cellulose (HEC): Hydroxyethyl cellulose e thehoa ka ho hlahisa li-substituents tsa hydroxyethyl (-OC₂H₅), e leng se etsang hore e se ke ea qhibiliha ka metsing le ho thibela letsoai. HEC e atisa ho sebelisoa ka litlolo tse entsoeng ka metsi, lipente tsa latex le lisebelisoa tsa mohaho. E na le thepa e ntle ea ho tenya le ho etsa lifilimi mme e ka ntlafatsa haholo ts'ebetso ea kaho ea thepa.
Hydroxypropyl methylcellulose (HPMC): Hydroxypropyl methylcellulose e thehoa ka kenyelletso ea nako e le 'ngoe ea hydroxypropyl (-CH₂CHOHCH₃) le li-substituents tsa methyl. Mofuta ona oa cellulose ether o bonts'a ho bolokoa ha metsi ka mokhoa o babatsehang, lubricity le ts'ebetso ea thepa ea mohaho e kang seretse se omeletseng, li-adhesives tsa lithaele, le mekhoa ea ho kenya marako ka ntle. HPMC e boetse e na le ho hanyetsa mocheso o motle le ho hanyetsa serame, kahoo e ka ntlafatsa ka katleho ts'ebetso ea thepa ea mohaho tlas'a maemo a leholimo a feteletseng.
3. Ho qhibiliha ha metsi le ho teteaneng
Ho qhibiliha ha metsi ha cellulose ether ho ipapisitse le mofuta le tekanyo ea phalliso ea ntho e nkeloang sebaka (ke hore, palo ea lihlopha tsa hydroxyl tse nketsoeng sebakeng sa yuniti ka 'ngoe ea tsoekere). Tekanyo e nepahetseng ea ho nka sebaka e thusa limolek'hule tsa cellulose ho etsa tharollo e ts'oanang metsing, e fanang ka thepa e ntle ea ho teteana. Lisebelisoa tsa mohaho, li-cellulose ethers e le li-thickeners li ka eketsa viscosity ea seretse, ho thibela stratification le ho arohana ha thepa, 'me kahoo ho ntlafatsa ts'ebetso ea kaho.
4. Ho boloka metsi
Ho boloka metsi a cellulose ether ke habohlokoa ho boleng ba thepa ea mohaho. Ka lihlahisoa tse kang seretse le putty powder, cellulose ether e ka etsa filimi e teteaneng ea metsi holim'a thepa ho thibela metsi hore a se ke a fetoha mouoane ka potlako, kahoo a eketsa nako e bulehileng le ho sebetsa ha thepa. Sena se phetha karolo ea bohlokoa ho ntlafatsa matla a ho kopanya le ho thibela ho phunyeha.
5. Rheology le ts'ebetso ea kaho
Ho eketsoa ha cellulose ether ho ntlafatsa haholo thepa ea rheological ea thepa ea mohaho, ke hore, ho phalla le boitšoaro ba deformation ea thepa tlas'a matla a ka ntle. E ka ntlafatsa ho boloka metsi le lubricity ea seretse, eketsa pompong le boiketlo ba kaho ea thepa. Ts'ebetsong ea kaho e kang ho fafatsa, ho senya le ho haha masonry, cellulose ether e thusa ho fokotsa ho hanyetsa le ho ntlafatsa katleho ea mosebetsi, ha ho ntse ho netefatsa hore ho roala junifomo ntle le ho senya.
6. Ho lumellana le ho sireletsa tikoloho
Cellulose ether e na le tumellano e ntle le mefuta e sa tšoaneng ea thepa ea mohaho, ho akarelletsa le samente, gypsum, lime, joalo-joalo Nakong ea ts'ebetso ea kaho, e ke ke ea itšoara hampe le likarolo tse ling tsa lik'hemik'hale ho netefatsa botsitso ba thepa. Ho phaella moo, cellulose ether ke motsoako o motala le oa tikoloho, oo haholo-holo o tsoang ho likhoele tsa tlhaho tsa limela, ha o kotsi ho tikoloho, 'me o finyella litlhoko tsa tšireletso ea tikoloho ea thepa ea kajeno ea mohaho.
7. Lisebelisoa tse ling tse fetotsoeng
E le ho ntlafatsa ts'ebetso ea cellulose ether, lisebelisoa tse ling tse fetotsoeng li ka hlahisoa tlhahiso ea sebele. Ka mohlala, bahlahisi ba bang ba tla ntlafatsa ho hanyetsa metsi le ho hanyetsa boemo ba leholimo ba cellulose ether ka ho kopanya le silicone, parafine le lintho tse ling. Ho eketsoa ha metsoako ena e fetotsoeng hangata ke ho fihlela litlhoko tse khethehileng tsa ts'ebeliso, joalo ka ho eketsa bokhoni ba thepa e thibelang ho kenella le ho tšoarella ha lirafshoa tsa lebota le kantle kapa lirekere tse sa keneleng metsi.
E le karolo ea bohlokoa ea thepa ea mohaho, cellulose ether e na le lintho tse ngata tse sebetsang, tse kenyelletsang ho teteaneng, ho boloka metsi, le ho ntlafatsa thepa ea rheological. Likarolo tsa eona tsa mantlha ke sebopeho sa mantlha sa cellulose le li-substituent tse hlahisoang ke karabelo ea etherification. Mefuta e fapaneng ea ethers ea cellulose e na le ts'ebeliso le ts'ebetso e fapaneng ea thepa ea moaho ka lebaka la ho se tšoane ha li-substitute tsa tsona. Li-cellulose ethers li ke ke tsa ntlafatsa feela ts'ebetso ea kaho ea thepa, empa hape li ntlafatsa boleng ba kakaretso le bophelo ba tšebeletso ea mehaho. Ka hona, li-cellulose ethers li na le menyetla e pharaletseng ea ts'ebeliso ea thepa ea morao-rao ea mohaho.
Nako ea poso: Sep-18-2024