Karolo ea bohlokoa ea cellulose ether ka seretse se seng se lokisitsoe:
Ka seretse se itokiselitseng ho tsoaka, selulose ether palo e ekelitsoeng e tlase haholo, empa e ka ntlafatsa haholo ts'ebetso ea seretse se metsi, ts'ebetso ea kaho ea seretse ke tlatsetso e kholo.Khetho e loketseng ea mefuta e fapaneng, viscosity e fapaneng, boholo bo fapaneng ba likaroloana, tekanyo e fapaneng ea viscosity le ho eketsa palo ea cellulose ether.
Ka seretse se itokiselitseng ho tsoaka, selulose ether palo e ekelitsoeng e tlase haholo, empa e ka ntlafatsa haholo ts'ebetso ea seretse se metsi, ts'ebetso ea kaho ea seretse ke tlatsetso e kholo.Khetho e loketseng ea cellulose ether e nang le mefuta e fapaneng, viscosity e fapaneng, boholo bo fapaneng ba likaroloana, tekanyo e fapaneng ea viscosity le palo ea tlatsetso e na le phello e ntle ntlafatsong ea thepa ea seretse se omeletseng.Hajoale, liretse tse ngata tsa masonry le plastering li na le ts'ebetso e mpe ea ho boloka metsi, 'me karohano ea seretse sa metsi e tla etsahala kamora metsotso e seng mekae ea ho ema.
Ho boloka metsi ke ts'ebetso ea bohlokoa ea methyl cellulose ether, empa hape le bahlahisi ba bangata ba seretse se omeletseng sa malapeng, haholo-holo sebakeng se ka boroa sa bahlahisi ba mocheso o phahameng ba amehileng ka ts'ebetso.Lintlha tse amang phello ea ho boloka metsi ea seretse se omileng li kenyelletsa palo ea MC, viscosity ea MC, botle ba likaroloana le mocheso o teng.
Cellulose ether ke polymer ea maiketsetso e entsoeng ka selulose ea tlhaho e le thepa e tala ka phetoho ea lik'hemik'hale.Cellulose ether e tsoa ho cellulose ea tlhaho, tlhahiso ea cellulose ether le polymer ea maiketsetso e fapane, thepa ea eona ea mantlha ke selulose, metsoako ea polima ea tlhaho.Ka lebaka la sebopeho sa cellulose ea tlhaho, selulose ka boeona ha e na matla a ho itšoara ka etherifying agent.Leha ho le joalo, ka mor'a ho phekoloa ha moemeli oa ho ruruha, likamano tse matla tsa hydrogen pakeng tsa liketane tsa molek'hule le ka har'a ketane li ile tsa senngoa, 'me mosebetsi oa sehlopha sa hydroxyl o ile oa lokolloa ka selulose ea alkali e nang le bokhoni ba ho itšoara,' me cellulose ether e ile ea fumanoa ka ho itšoara ha moemeli oa ETHERifying - OH sehlopha ho -OR sehlopha.
Thepa ea cellulose ethers e itšetlehile ka mofuta, palo le kabo ea li-substituent.Sehlopha sa cellulose ether se boetse se ipapisitse le mofuta oa li-substituent, tekanyo ea etherification, solubility le ts'ebeliso e amanang le eona e ka aroloa.Ho ea ka mofuta oa li-substituents tsa ketane ea molek'hule, e ka aroloa ka ether e le 'ngoe le ether e tsoakiloeng.MC hangata e sebelisoa joalo ka ether e le 'ngoe, ha HPMC e le ether e tsoakiloeng.Methyl cellulose ether MC ke yuniti ea tsoekere ea cellulose ea tlhaho ho hydroxyl methoxide e nkeloang sebaka ke foromo ea sebopeho sa sehlahisoa ke [COH7O2 (OH) 3-H (OCH3) H] X, hydroxypropyl methyl cellulose ether HPMC ke yuniti e karolong ea hydroxyl ea methoxide e nkeloa sebaka ke hydroxypropyl, karolo e 'ngoe ea sehlahisoa e nkeloa sebaka ke hydroxypropyl, Foromo ea sebopeho ke [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X le hydroxyethyl methyl cellulose ether HEMC, e leng e sebelisoang haholo le e rekisoang 'marakeng.
Ho tsoa ho solubility ho ka aroloa ka mofuta oa ionic le mofuta o seng oa ionic.Metsi a qhibilihang a non-ionic cellulose ether haholo-holo a entsoe ka alkyl ether le hydroxyl alkyl ether tse peli tsa mefuta e sa tšoaneng.Ionic CMC e sebelisoa haholo ho sesepa sa maiketsetso, masela, khatiso, lijo le tšebeliso ea peterole.Non-ionic MC, HPMC, HEMC le tse ling tse sebelisoang haholo ka thepa ea mohaho, liphahlo tsa latex, meriana, k'hemistri ea letsatsi le letsatsi le likarolo tse ling.Joalo ka motenya, moemeli oa ho boloka metsi, stabilizer, dispersant, moemeli oa ho etsa filimi.
Cellulose ether ho boloka metsi: tlhahiso ea thepa ea mohaho, haholo-holo seretse se omileng, selulose ether e phetha karolo e ke keng ea nkeloa sebaka, haholo-holo tlhahiso ea seretse se khethehileng (seretse se fetotsoeng), empa hape ke karolo ea bohlokoa.Karolo ea bohlokoa ea selulose e qhibilihang ka metsing ka seretse e na le likarolo tse tharo, e 'ngoe ke bokhoni bo babatsehang ba ho boloka metsi, ea bobeli ke tšusumetso ea ho lumellana ha seretse le thixotropy,' me ea boraro ke ho sebelisana le samente.Ho boloka metsi a cellulose ether, ho ipapisitse le motheo oa hydroscopicity, sebopeho sa seretse, botenya ba seretse, tlhokahalo ea metsi a seretse, nako ea condensation ea thepa ea condensation.Palo ea metsi ea cellulose ether e tsoa ho solubility le dehydration ea cellulose ether ka boeona.Hoa tsebahala hore liketane tsa limolek'hule tsa cellulose, le hoja li na le palo e kholo ea lihlopha tsa OH tse nang le metsi a mangata, ha li khone ho qhibiliha metsing ka lebaka la sebopeho sa tsona sa kristale e ngata.Bokhoni ba hydration ba lihlopha tsa hydroxyl feela ha boa lekana ho lefella li-intermolecular hydrogen bond le matla a van der Waals.Ha substituents hlahiswa ka ketane ea molek'hule, e seng feela substituents senya ketane ea haedrojene, empa hape le ditlamo interchain hydrogen li robehile ka lebaka la wedging ea substituents pakeng tsa liketane tse haufi.Tse kholoanyane tse nkang sebaka, sebaka se pakeng tsa limolek'hule se seholo.The timetso e kholoanyane ea phello ea hydrogen bond, katoloso ea selulose lattice, tharollo ka har'a selulose ether e fetoha qhibilihang ka metsing, ho thehoa ha tharollo e phahameng ea viscosity.Ha mocheso o ntse o phahama, hydration ea polymer e fokotseha 'me metsi a pakeng tsa liketane a lelekoa.Ha phello ea dehydrating e lekane, limolek'hule li qala ho bokellana 'me gel e phuthoa ka marang-rang a mararo.
Lintlha tse amang ho bolokoa ha metsi ka seretse li kenyelletsa cellulose ether viscosity, litekanyetso, botle ba likaroloana le mocheso oa ts'ebeletso.
Ha ho na le viscosity e kholo ea cellulose ether, ho na le ts'ebetso e ntle ea ho boloka metsi.Viscosity ke karolo ea bohlokoa ea ts'ebetso ea MC.Hajoale, bahlahisi ba fapaneng ba MC ba sebelisa mekhoa le lisebelisoa tse fapaneng ho lekanya viscosity ea MC.Mekhoa e meholo e kenyelletsa Haake Rotovisko, Hoppler, Ubbelohde le Brookfield.Bakeng sa sehlahisoa se tšoanang, liphetho tsa viscosity tse lekantsoeng ka mekhoa e fapaneng li fapane haholo, tse ling li bile li fapane.Ka hona, ha ho bapisoa viscosity, e tlameha ho etsoa pakeng tsa mokhoa o tšoanang oa teko, ho kenyelletsa mocheso, rotor, joalo-joalo.
Ha re bua ka kakaretso, ha viscosity e phahame, phello e ntle ea ho boloka metsi.Leha ho le joalo, ha viscosity e phahame, boima ba limolek'hule ba MC bo phahame, 'me ts'ebetso ea ho qhibiliha e tla fokotseha ka tsela e ts'oanang, e nang le tšusumetso e mpe ho matla le ts'ebetso ea kaho ea seretse.Ho phahama ha viscosity, ho hlakile haholoanyane phello e teteaneng ea seretse, empa ha e lekane le kamano.Ha li-viscosity li phahame, seretse se metsi se tla khomarela haholoanyane, ka bobeli ho haha, ts'ebetso ea "Stick scraper" le ho khomarela holimo ho thepa ea motheo.Empa ha ho na thuso ho eketsa matla a sebopeho sa seretse se metsi.Nakong ea kaho, ts'ebetso ea anti-sag ha e hlake.Ho fapana le hoo, li-viscosity tse ling tse tlase empa li-ether tsa methyl cellulose tse fetotsoeng li na le ts'ebetso e ntle haholo ho ntlafatsa matla a sebopeho sa seretse se metsi.
Ha cellulose ether e eketsoa ho seretse, ts'ebetso e ntle ea ho boloka metsi, e phahamisa viscosity, ts'ebetso e ntle ea ho boloka metsi.
Bakeng sa boholo ba likaroloana, ha karoloana e le ntle, ho boloka metsi ho molemo.Likaroloana tse kholo tsa selulose ether li kopana le metsi, ka holim'a metsi hang-hang li qhibiliha ebe li etsa gel ho phuthela lintho tse bonahalang ho thibela limolek'hule tsa metsi ho tsoela pele ho kenella, ka linako tse ling nako e telele e tsosang takatso e ke ke ea qhalakanngoa ka mokhoa o ts'oanang, ho thehoa ha tharollo ea seretse kapa agglomerate.The solubility ea cellulose ether ke e 'ngoe ea lintlha tsa ho khetha cellulose ether.Fineness hape ke index ea bohlokoa ea ts'ebetso ea methyl cellulose ether.MC bakeng sa seretse se omeletseng se hloka phofo, metsi a tlaase, le fineness ea 20% ~ 60% ea boholo ba likaroloana tse ka tlaase ho 63um.Fineness e ama ho qhibiliha ha methyl cellulose ether.Coarse MC hangata ke granular 'me e ka qhibiliha habonolo ka metsing ntle le agglomerating, empa lebelo la ho qhibiliha le lieha haholo, kahoo ha lea lokela ho sebelisoa ka seretse se omileng.Ka seretse se omeletseng, MC e qhalakantsoeng pakeng tsa li-aggregate, li-fillers tse ntle le lisebelisoa tsa samente tse kang samente, 'me ke phofo feela e lekaneng e ka qobang ho bokellana ha methyl cellulose ether ha e kopanya le metsi.Ha MC e eketsa metsi ho qhaqha agglomerate, ho thata haholo ho e qhala le ho e qhaqha.MC ka fineness mahoashe eseng feela litšila, empa hape ho fokotsa matla a sebaka sa seretse.Ha seretse se joalo se ommeng se hahoa sebakeng se seholo, lebelo la ho folisa la seretse se omeletseng sa sebakeng seo le fokotseha haholo, e leng se bakang ho phunyeha ho bakoang ke nako e fapaneng ea ho phekola.Bakeng sa seretse sa ho fafatsa ka mochini, ka lebaka la nako e khuts'oane ea ho kopanya, botle bo phahame.
Botle ba MC bo boetse bo na le tšusumetso e itseng ho bolokeng metsi ha eona.Ha re bua ka kakaretso, bakeng sa methyl cellulose ether e nang le viscosity e ts'oanang empa botle bo fapaneng, phello e ntle ea ho boloka metsi e ba betere ha e ntse e eketseha.
Ho boloka metsi a MC ho boetse ho amana le mocheso o sebelisoang, 'me ho boloka metsi a methyl cellulose ether ho fokotseha ka ho phahama ha mocheso.Empa ts'ebelisong ea 'nete ea lintho tse bonahalang, libaka tse ngata tsa seretse se omileng hangata li tla ba mocheso o phahameng (o fetang likhato tse 40) tlas'a maemo a kaho ka substrate e chesang, joalo ka hlabula e insolation ea bokantle ba lerako la putty plaster, eo hangata e potlakisang ho tiisa. samente le seretse se ommeng se thatafatsang.Ho fokotseha ha sekhahla sa ho boloka metsi ho lebisa maikutlong a totobetseng a hore bobeli ba ho hahoa le ho hanyetsa ho phunyeha ho ameha.Boemong bona, ho fokotsa tšusumetso ea lintlha tsa mocheso ho ba bohlokoa haholo.Le hoja tlatsetso ea methyl hydroxyethyl cellulose ether e nkoa e le eona e ka pele-pele ho nts'etsopele ea theknoloji, ho itšetleha ha eona ho mocheso ho ntse ho tla lebisa ho fokotseng thepa ea seretse se omileng.Leha ho e-na le keketseho ea tekanyo ea methyl hydroxyethyl cellulose (formula ea lehlabula), khanyetso ea kaho le ho phunyeha e ntse e sa khone ho finyella litlhoko tsa tšebeliso.Ka phekolo e khethehileng ea MC, e kang ho eketsa tekanyo ea etherification, phello ea ho boloka metsi ea MC e ka boloka phello e ntle tlas'a mocheso o phahameng, e le hore e ka fana ka ts'ebetso e ntlafetseng tlas'a maemo a thata.
Ho phaella moo, cellulose ether thickening le thixotropy: cellulose ether ketso ea bobeli - thickening e itšetlehile ka: cellulose ether polymerization degree, mahloriso a tharollo, sekhahla sa shear, mocheso le maemo a mang.Thepa ea gelation ea tharollo e ikhethile ho alkyl cellulose le li-derivatives tsa eona tse fetotsoeng.Litšobotsi tsa gelation li amana le tekanyo ea ho fetola, mahloriso a tharollo le li-additives.Bakeng sa li-derivatives tse fetotsoeng tsa hydroxyl alkyl, thepa ea gel e boetse e amana le tekanyo ea phetoho ea hydroxyl alkyl.Bakeng sa tharollo mahloriso a tlaase viscosity MC le HPMC ka lokisoa 10% -15% mahloriso tharollo, mahareng viscosity MC le HPMC ka lokisoa 5% -10% tharollo, 'me phahameng viscosity MC le HPMC ka feela lokisetsa 2% -3. % tharollo, 'me hangata selulose ether viscosity grading e boetse e le 1% -2% tharollo ea kereiti.Boima bo phahameng ba cellulose ether thickener e sebetsang hantle, motsoako o tšoanang oa tharollo, li-polymers tse fapaneng tsa boima ba molek'hule li na le viscosity e fapaneng, viscosity le boima ba molek'hule li ka hlalosoa ka tsela e latelang, [η] = 2.92 × 10-2 (DPn) 0.905, DPn ke karolelano polymerization tekanyo e phahameng.Low molecular weight cellulose ether ho eketsa ho feta ho finyella sepheo sa viscosity.Viscosity ea eona ha e itšetlehe haholo ka sekhahla sa ho kuta, viscosity e phahameng ho fihlela sepheo sa viscosity, chelete e hlokahalang ho eketsa hanyane, viscosity e itšetlehile ka katleho e ntseng e eketseha.Ka hona, ho finyella ho ts'oana ho itseng, palo e itseng ea cellulose ether (concentration of solution) le viscosity ea tharollo e tlameha ho tiisetsoa.Mocheso oa mocheso oa tharollo o fokotsehile ka mokhoa o ts'oanang le ho eketseha ha motsoako oa tharollo, 'me gelation e etsahetse mocheso oa kamore ka mor'a ho fihla mohopolong o itseng.HPMC e na le mocheso o phahameng oa gelation mocheso oa kamore.
Ho lumellana ho ka boela ha fetoloa ka ho khetha boholo ba likaroloana le li-cellulose ethers tse nang le likhato tse fapaneng tsa phetoho.Seo ho thoeng ke phetoho ke ho kenyelletsoa ha sehlopha sa hydroxyl alkyl ka tekanyo e itseng ea ho fetola sebopeho sa skeleton sa MC.Ka ho fetola litekanyetso tse lekanyelitsoeng tsa phapanyetso ea li-substitute tse peli, ke hore, DS le MS e amanang le phapanyetso ea boleng ba lihlopha tsa methoxy le hydroxyl.Mefuta e fapaneng ea ether ea cellulose e hlokahala ka ho fetola boleng ba mefuta e 'meli ea li-substitute.
Kamano pakeng tsa ho tsitsa le ho fetola: ho eketsoa ha cellulose ether ho ama tšebeliso ea metsi ea seretse, 'me ho fetola tekanyo ea metsi-binder ea metsi le samente, e leng phello e teteaneng.Ha tekanyo ea litekanyetso e phahame, ho sebelisoa metsi a mangata.
Li-cellulose ethers tse sebelisoang ka thepa ea mohaho oa phofo li tlameha ho qhibiliha ka potlako metsing a batang 'me li fane ka mokhoa o nepahetseng oa tsamaiso.Haeba tekanyo e fanoeng ea ho kuta e ntse e phalla 'me e le colloidal ke sehlahisoa sa boleng bo tlaase kapa se tlaase.
Ho boetse ho na le kamano e ntle pakeng tsa samente slurry consistency le tekanyo ea cellulose ether, cellulose ether e ka eketsa viscosity ea seretse haholo, e kholoanyane lethal dose, le phello e hlakileng haholoanyane.Cellulose ether aqueous solution e nang le viscosity e phahameng e na le thixotropy e phahameng, e leng e 'ngoe ea litšobotsi tsa cellulose ether.Litharollo tsa metsi tsa mofuta oa MC polymers hangata li na le pseudoplastic, non-thixotropic fluidity ka tlase ho mocheso oa bona oa gel, empa thepa ea phallo ea Newtonian ka litheko tse tlase tsa ho kuta.Pseudoplasticity e eketseha ka ho eketseha ha boima ba limolek'hule kapa khatello ea cellulose ether 'me e ikemela ho latela mofuta le degree.Ka hona, li-cellulose ethers tsa sehlopha se tšoanang sa viscosity, ebang ke MC, HPMC kapa HEMC, kamehla li bontša litšobotsi tse tšoanang tsa rheological hafeela mahloriso le mocheso li lula li le teng.Ha mocheso o ntse o eketseha, gel ea mohaho e thehoa 'me phallo e phahameng ea thixotropic e etsahala.Li-cellulose ethers tse nang le mahloriso a phahameng le li-viscosity tse tlaase li bonts'a thixotropy esita le ka tlase ho mocheso oa gel.Thepa ena e na le molemo o moholo kahong ea seretse sa moaho ho lokisa phallo ea eona le thepa e leketlileng.Ho hlokahala hore ho hlalosoe mona hore ho phahama ha viscosity ea cellulose ether, ho boloka metsi ho molemo, empa ho phahama ha viscosity, ho phahamisa boima ba molek'hule ea cellulose ether, ho fokotseha ho lumellanang ha solubility ea eona, e nang le phello e mpe ho mahloriso a seretse le ts'ebetso ea kaho.Ho phahama ha viscosity, ho hlakile haholoanyane phello e teteaneng ea seretse, empa ha se kamano e feletseng ea tekano.Li-viscosity tse ling tse tlase, empa ether ea selulose e fetotsoeng ho ntlafatsa matla a sebopeho sa seretse se metsi se na le ts'ebetso e ntle haholo, ka keketseho ea viscosity, ho boloka metsi a cellulose ether ho ntlafalitsoe.
Cellulose ether retardation: cellulose ether karolo ea boraro ke ho liehisa tšebetso ea hydration ea samente.Cellulose ether e fana ka seretse se nang le lisebelisoa tse fapaneng tse molemo, empa hape e fokotsa ho lokolloa ha mocheso oa pele oa samente, ho liehisa ts'ebetso e matla ea hydration ea samente.Sena ha se monate ho sebelisa seretse libakeng tse batang.Mofuta ona oa phello ea ho fokotsa ke cellulose ether molek'hule adsorption ho CSH le Ca (OH) 2 lihlahisoa tsa hydration tse bakoang ke, ka lebaka la ho eketseha ha pore solution viscosity, cellulose ether e fokotsa mosebetsi oa li-ion tharollo, kahoo e liehisa ts'ebetso ea hydration.Ha palo ea cellulose ether e phahame ka har'a lisebelisoa tsa gel ea liminerale, phello ea ho lieha ha hydration e bonahala haholoanyane.Cellulose ether ha e liehe feela ho beha, empa hape le ts'ebetso e thata ea tsamaiso ea seretse sa samente.Phello e fokolisang ea cellulose ether ha e itšetlehe feela ka mahloriso a eona tsamaisong ea gel ea diminerale, empa hape le sebopeho sa lik'hemik'hale.Ha tekanyo ea HEMC methylation e phahame, e ntlafatsa phello ea ho fokotsa cellulose ether.Phello e fokolisang ea hydrophilic replacement e matla ho feta ea phetisetso e ntseng e eketseha ea metsi.Empa viscosity ea cellulose ether ha e na phello e fokolang ho hydration kinetics ea samente.
Ka keketseho ea cellulose ether content, nako ea ho beha seretse e eketseha haholo.Nako ea pele ea ho beha seretse e na le kamano e ntle ea linear le litaba tsa cellulose ether, 'me nako ea ho qetela ea ho beha e na le kamano e ntle ea linear le litaba tsa cellulose ether.Re ka laola nako ea ts'ebetso ea seretse ka ho fetola tekanyo ea cellulose ether.
Ho akaretsa, ka seretse se kopantsoeng se lokiselitsoeng, cellulose ether e phetha karolo ea ho boloka metsi, ho teteaneng, ho lieha ho matlafatsa samente, ho ntlafatsa ts'ebetso ea kaho.Bokhoni bo botle ba ho boloka metsi bo etsa hore hydration ea samente e phethehe haholoanyane, e ka ntlafatsa viscosity e metsi ea seretse se metsi, ea ntlafatsa matla a tlamahano ea seretse, nako e feto-fetohang.Ho kenyelletsa cellulose ether ho seretse sa ho fafatsa ka mochini ho ka ntlafatsa ts'ebetso ea ho fafatsa kapa ho pompa le matla a sebopeho sa seretse.Ka hona, ether ea cellulose e sebelisoa haholo e le tlatsetso ea bohlokoa ka seretse se seng se kopantsoe.
Nako ea poso: Dec-17-2021