Focus on Cellulose ethers

Karolo ea bohlokoa ea cellulose ether ka seretse

Cellulose ether e ka ntlafatsa haholo ts'ebetso ea seretse se metsi, 'me ke tlatsetso e kholo e amang ts'ebetso ea kaho ea seretse. Khetho e utloahalang ea li-cellulose ethers tsa mefuta e sa tšoaneng, li-viscosities tse fapaneng, boholo bo fapaneng ba likaroloana, likhato tse fapaneng tsa viscosity le chelete e eketsehileng e tla ba le phello e ntle ntlafatsong ea ts'ebetso ea seretse se omeletseng sa phofo. Hajoale, liretse tse ngata tsa masonry le plastering li na le ts'ebetso e mpe ea ho boloka metsi, 'me seretse sa metsi se tla arohana kamora metsotso e seng mekae ea ho ema. Ho boloka metsi ke ts'ebetso ea bohlokoa ea methyl cellulose ether, hape ke ts'ebetso eo bahlahisi ba bangata ba seretse se ommeng malapeng, haholo-holo ba libakeng tse ka boroa tse nang le mocheso o phahameng, ba e ela hloko. Lintlha tse amang phello ea ho boloka metsi ea seretse sa phofo e omileng li kenyelletsa palo ea ho eketsa, viscosity, fineness ea likaroloana, le mocheso oa tikoloho ea tšebeliso.

Ho boloka metsi a cellulose ether

Ha ho etsoa thepa ea ho haha, haholo-holo phofo e omeletseng ea seretse, cellulose ether e phetha karolo e ke keng ea nkeloa sebaka, haholo-holo tlhahiso ea seretse se khethehileng (seretse se fetotsoeng), ke karolo ea bohlokoa le 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, e' ngoe ke tšusumetso ea ho lumellana le thixotropy ea seretse, 'me ea boraro ke ho sebelisana le samente. Phello ea ho boloka metsi ea cellulose ether e itšetlehile ka ho kenngoa ha metsi a lera la motheo, sebopeho sa seretse, botenya ba lera la seretse, tlhokahalo ea metsi ea seretse, le nako ea ho beha thepa. Ho boloka metsi a cellulose ether ka boeona ho tsoa ho solubility le dehydration ea cellulose ether ka boeona. Joalokaha bohle re tseba, le hoja ketane ea molek'hule ea cellulose e na le palo e kholo ea lihlopha tsa OH tse nang le metsi a mangata haholo, ha e qhibilihe ka metsing, hobane sebopeho sa cellulose se na le tekanyo e phahameng ea crystallinity. Bokhoni ba hydration ba lihlopha tsa hydroxyl feela ha boa lekana ho koahela litlamo tse matla tsa hydrogen le matla a van der Waals pakeng tsa limolek'hule. Ka hona, e ruruha feela empa ha e qhibilihe ka metsing. Ha substituent e hlahiswa ka ketane ea limolek'hule, e seng feela substituent timetsa ketane ea haedrojene, empa hape interchain hydrogen tlamo timetsoa ka lebaka la wedging ea substituent pakeng tsa liketane tse haufi. Ha sebaka se seng se le seholo, sebaka se pakeng tsa limolek'hule se ba seholoanyane. Bohole bo boholo. Phello e kholoanyane ea ho senya likamano tsa hydrogen, cellulose ether e fetoha metsi a qhibilihang ka mor'a hore lesela la cellulose le atolohe 'me tharollo e kene, e etsa tharollo e phahameng ea viscosity. Ha mocheso o phahama, hydration ea polymer e fokotseha, 'me metsi a pakeng tsa liketane a lelekoa. Ha phello ea ho felloa ke metsi e lekane, limolek'hule li qala ho bokellana, ho etsa gel ea sebopeho sa marang-rang a mararo le ho phuthoa.

Ha re bua ka kakaretso, ha viscosity e phahame, phello e ntle ea ho boloka metsi. Leha ho le joalo, ha viscosity e phahame 'me boima ba limolek'hule bo phahame, ho fokotseha ho lekanang le ho qhibiliha ha eona ho tla ba le tšusumetso e mpe ho matla le ts'ebetso ea kaho ea seretse. Ha li-viscosity li phahame, ho hlakile haholoanyane phello e teteaneng holim'a seretse, empa ha e lekane ka ho toba. Ha li-viscosity li phahame, seretse se metsi se tla ba le viscous haholoanyane, ke hore, nakong ea kaho, se bonahatsoa e le ho khomarela sekoti le ho khomarela holimo ho substrate. Empa ha ho na thuso ho eketsa matla a sebopeho sa seretse se metsi ka boeona. Nakong ea kaho, ts'ebetso ea anti-sag ha e hlake. Ho fapana le hoo, li-viscosity tse ling tse mahareng le tse tlase empa tse fetotsoeng tsa methyl cellulose ethers li na le ts'ebetso e ntle haholo ho ntlafatsa matla a sebopeho sa seretse se metsi.

Thickening le Thixotropy ea Cellulose Ether

Ho boetse ho na le kamano e ntle pakeng tsa ho lumellana ha pente ea samente le tekanyo ea cellulose ether. Cellulose ether e ka eketsa viscosity ea seretse haholo. Ha tekanyo e le kholoanyane, phello e totobetse haholoanyane. High-viscosity cellulose ether aqueous solution e na le thixotropy e phahameng, eo hape e leng tšobotsi e kholo ea cellulose ether.

Thickening e itšetlehile ka tekanyo ea polymerization ea cellulose ether, mahloriso a tharollo, sekhahla sa ho kuta, mocheso le maemo a mang. Thepa ea gelling ea tharollo e ikhethile ho alkyl cellulose le lihlahisoa tsa eona tse fetotsoeng. Thepa ea gelation e amana le tekanyo ea ho fetola, mahloriso a tharollo le li-additives. Bakeng sa li-derivatives tse fetotsoeng tsa hydroxyalkyl, thepa ea gel e boetse e amana le boemo ba phetoho ea hydroxyalkyl. Bakeng sa viscosity tlaase MC le HPMC, 10% -15% tharollo ka lokisoa, mahareng viscosity MC le HPMC ka lokisoa 5% -10% tharollo, ha phahameng viscosity MC le HPMC ka feela lokisetsa 2% -3% tharollo, 'me Hangata. sehlopha sa viscosity sa cellulose ether se boetse se hlophisoa ka tharollo ea 1% -2%. Limolek'hule tse phahameng tsa cellulose ether li na le bokhoni bo phahameng ba ho tiea. Tharollong e tšoanang ea mahloriso, li-polymer tse nang le boima bo fapaneng ba limolek'hule li na le li-viscosity tse fapaneng. Tekanyo e phahameng. Sepheo sa viscosity se ka finyelloa feela ka ho eketsa palo e kholo ea boima bo tlaase ba molek'hule cellulose ether. Viscosity ea eona ha e itšetlehe haholo ka sekhahla sa ho kuta, 'me viscosity e phahameng e fihla ho viscosity e reriloeng,' me palo e hlokahalang ea tlatsetso e nyane, 'me viscosity e ipapisitse le katleho e kholo. Ka hona, ho finyella ts'ebetso e itseng, palo e itseng ea cellulose ether (ho tsepamisa maikutlo ho tharollo) le viscosity ea tharollo e tlameha ho tiisetsoa. Mocheso oa mocheso oa gel oa tharollo o boetse o fokotseha ka mokhoa o ts'oanang le ho eketseha ha motsoako oa tharollo, le li-gel ka mocheso oa motsoako ka mor'a hore li fihle boemong bo itseng. Motsoako oa gelling oa HPMC o batla o phahame mocheso oa kamore.

Ho fokotseha ha Cellulose Ether

Mosebetsi oa boraro oa cellulose ether ke ho liehisa ts'ebetso ea hydration ea samente. Cellulose ether e fana ka seretse se nang le lisebelisoa tse fapaneng tse molemo, hape e fokotsa mocheso oa pele oa hydration oa samente le ho liehisa ts'ebetso ea hydration e matla ea samente. Sena ha se monate bakeng sa tšebeliso ea seretse libakeng tse batang. Phello ena ea ho lieha e bakoa ke ho ata ha limolek'hule tsa cellulose ether lihlahisoa tsa hydration tse kang CSH le ca(OH)2. Ka lebaka la ho eketseha ha viscosity ea tharollo ea pore, cellulose ether e fokotsa ho tsamaea ha li-ion ka 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 e liehisa mokhoa o thata oa 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 methylation ea HEMC e phahame, e ntlafatsa phello ea ho fokotsa cellulose ether. Karo-karolelano ea hydrophilic substitution ho metsi-e ntseng e eketseha Phapanyetsano ea ho khutlisa e matla. Leha ho le joalo, viscosity ea cellulose ether ha e na phello e nyane ho samente hydration kinetics.

Ka seretseng, cellulose ether e bapala karolo ea ho boloka metsi, ho teteana, ho liehisa matla a samente a hydration, le 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 eketsa matla a tlamahano ea seretse, le ho lokisa nako. 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 har'a seretse se seng se kopantsoe


Nako ea poso: Dec-26-2022
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