I-ether ye-cellulose ligama eliqhelekileyo loluhlu lweemveliso eziveliswa yi-reaction ye-alkali cellulose kunye ne-etherifying agent phantsi kweemeko ezithile. I-alkali cellulose ithathelwa indawo ngama-agent ahlukeneyo e-etherifying ukufumana ii-ethers ze-cellulose ezahlukeneyo. Ngokweempawu ze-ionization yezinto ezithatha indawo, i-cellulose ethers inokwahlulwa ibe ngamacandelo amabini: ionic (efana ne-carboxymethyl cellulose) kunye ne-nonionic (efana ne-methyl cellulose). Ngokohlobo lwe-substituent, i-cellulose ether inokohlulwa ibe yi-monoether (efana ne-methyl cellulose) kunye ne-ether edibeneyo (efana ne-hydroxypropyl methyl cellulose). Ngokwe-solubility eyahlukeneyo, inokwahlulwa ibe yi-solubility yamanzi (efana ne-hydroxyethyl cellulose) kunye ne-organic solvent solubility (efana ne-ethyl cellulose). Udaka oluxubeneyo elomileyo luyi-cellulose enyibilikayo emanzini, kwaye i-cellulose enyibilikayo emanzini yahlulwe ibe luhlobo olukhawulezileyo kunye nohlobo lokupheliswa kokulibaziseka okunyangwayo.
Indlela yokusebenza ye-cellulose ether kumdaka ihamba ngolu hlobo lulandelayo:
(1) Emva kokuba i-ether cellulose kumdaka inyibilikiswe emanzini, ukuhanjiswa okusebenzayo kunye okufanayo kwesixhobo se-cementitious kwinkqubo kuqinisekiswa ngenxa yomsebenzi ongaphezulu, kunye ne-cellulose ether, njenge-colloid ekhuselayo, "isonga" into eqinileyo. amasuntswana kunye Umaleko wefilimu yokuthambisa yenziwe kwindawo yayo yangaphandle, eyenza inkqubo yodaka iqine ngakumbi, kwaye iphucula umbane wodaka ngexesha lokuxuba kunye nokugudiswa kokwakhiwa.
(2) Ngenxa yeempawu zayo zesakhiwo semolekyuli, isisombululo se-ether se-cellulose senza ukuba ukufuma kwi-mortar kungabi lula ukulahlekelwa, kwaye ngokuthe ngcembe kuyayikhulula ngexesha elide, inika udaka ngokugcina amanzi kunye nokusebenza kakuhle.
1. Methylcellulose: (MC)
Emva kokuba umqhaphu osulungekisiweyo uphathwe ngealkali, i-cellulose ether iveliswa ngothotho lweempendulo ngemethane chloride njenge-etherification agent. Ngokubanzi, iqondo lokutshintsha liyi-1.6 ~ 2.0, kwaye ukunyibilika kwahluka ngokwamanqanaba okutshintsha. yeye-non-ionic cellulose ether.
(1) I-Methylcellulose iyanyibilika emanzini abandayo, kwaye kuya kuba nzima ukuyinyibilika emanzini ashushu. Isisombululo saso samanzi sizinzile kakhulu kuluhlu lwe-pH = 3 ~ 12. Inokuhambelana kakuhle nestatshi, i-guar gum, njl. kunye nee-surfactants ezininzi. Xa iqondo lokushisa lifikelela kwiqondo lokushisa, i-gelation iyenzeka.
(2) Ukugcinwa kwamanzi kwe-methyl cellulose kuxhomekeke kwisixa sokongeza, i-viscosity, i-particle fineness kunye nesantya sokuchithwa. Ngokuqhelekileyo, ukuba isixa esongezelelweyo sikhulu, i-fineness incinci, kwaye i-viscosity inkulu, izinga lokugcinwa kwamanzi liphezulu. Phakathi kwabo, inani lokongezelela linempembelelo enkulu kwizinga lokugcinwa kwamanzi, kwaye inqanaba le-viscosity alilingani ngokuthe ngqo kwinqanaba lokugcinwa kwamanzi. Izinga lokuchithwa ikakhulu lixhomekeke kwiqondo lokuguqulwa komphezulu we-cellulose particleness kunye ne-particle fineness. Phakathi kwezi zingentla ze-cellulose ethers, i-methyl cellulose kunye ne-hydroxypropyl methyl cellulose zinezinga eliphezulu lokugcina amanzi.
(3) Utshintsho kwiqondo lobushushu luya kuchaphazela kakhulu izinga lokugcinwa kwamanzi kwi-methyl cellulose. Ngokuqhelekileyo, okukhona ubushushu buphezulu, kokukhona ukugcinwa kwamanzi kubi. Ukuba ubushushu bomdaka budlula i-40 ° C, ukugcinwa kwamanzi kwe-methyl cellulose kuya kuncitshiswa kakhulu, kuchaphazela kakhulu ukwakhiwa kodaka.
(4) I-Methyl cellulose inempembelelo ebalulekileyo ekwakhiweni nasekudibaniseni udaka. “Ukuncamatheliswa” apha kubhekiselele kumandla okudibanisa okuvakala phakathi kwesixhobo sofakelo somsebenzi kunye nenxalenye yodonga, oko kukuthi, ukuxhathisa kokucheba kodaka. I-adhesiveness iphezulu, ukuxhathisa i-shear yodaka kukhulu, kwaye amandla afunwa ngabasebenzi kwinkqubo yokusetyenziswa nawo mkhulu, kwaye ukusebenza kokwakhiwa kodaka kubi. Ukubambisana kwe-methyl cellulose kwinqanaba eliphakathi kwiimveliso ze-cellulose ether.
2. I-Hydroxypropyl methyl cellulose (HPMC):
IHydroxypropyl methylcellulose luhlobo lweselulosi oluphuma kunye nokusetyenziswa kwayo kuye kwanda ngokukhawuleza kwiminyaka yakutshanje. I-ether engeyiyo ionic cellulose exutywe ne-ether eyenziwe kwi-cotton ecocekileyo emva kwe-alkalization, isebenzisa i-propylene oxide kunye ne-methyl chloride njenge-etherification agent, ngokusebenzisa uluhlu lweempendulo. Iqondo lokutshintshwa ngokubanzi yi-1.2 ~ 2.0. Iimpawu zayo ziyahluka ngokuxhomekeka kumlinganiselo we-methoxyl umxholo we-hydroxypropyl.
(1) IHydroxypropyl methylcellulose inyibilika ngokulula emanzini abandayo, kwaye iya kudibana nobunzima ekunyibilikeni kumanzi ashushu. Kodwa ubushushu bayo be-gelation emanzini ashushu buphezulu kakhulu kune-methyl cellulose. Ukunyibilika kumanzi abandayo kuphuculwe kakhulu xa kuthelekiswa ne-methyl cellulose.
(2) I-viscosity ye-hydroxypropyl methylcellulose ihambelana nobunzima bayo be-molecular, kwaye ubukhulu be-molecular weight, buphezulu be-viscosity. Ubushushu buchaphazela i-viscosity yayo, njengoko izinga lokushisa linyuka, i-viscosity iyancipha. Nangona kunjalo, impembelelo ye-viscosity yayo ephezulu kunye nobushushu buphantsi kune-methyl cellulose. Isisombululo sayo sizinzile xa sigcinwe kwiqondo lokushisa.
(3) Ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, njl.
(4) I-Hydroxypropyl methylcellulose izinzile kwi-asidi kunye ne-alkali, kwaye isisombululo sayo samanzi sizinzileyo kakhulu kwi-pH = 2 ~ 12. I-Caustic soda kunye namanzi ekalika anempembelelo encinci ekusebenzeni kwayo, kodwa i-alkali inokukhawulezisa ukuchithwa kwayo kwaye yandise i-viscosity yayo. I-Hydroxypropyl methylcellulose izinzile kwiityuwa eziqhelekileyo, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity ye-hydroxypropyl methylcellulose isisombululo ivame ukunyuka.
(5) I-Hydroxypropyl methylcellulose inokuxutywa kunye ne-polymer compounds e-soluble yamanzi ukuze yenze isisombululo esifanayo kunye ne-viscosity ephezulu. Okufana ne-polyvinyl alcohol, i-starch ether, i-gum yemifuno, njl.
(6) I-Hydroxypropyl methylcellulose inokumelana ne-enzyme engcono kune-methylcellulose, kunye nokuba kunokwenzeka ukuchithwa kwe-enzymatic yesisombululo sayo kuncinci kune-methylcellulose.
(7) I-adhesion ye-hydroxypropyl methylcellulose kwisakhiwo sodaka iphezulu kune-methylcellulose.
3. I-Hydroxyethyl cellulose (HEC):
Yenziwe kwikotoni esulungekileyo ephathwe nge-alkali, kwaye iphendule nge-ethylene oxide njenge-etherification agent phambi kwe-acetone. Iqondo layo lokutshintshwa ngokubanzi liyi-1.5 ~ 2.0. Ine-hydrophilicity eyomeleleyo kwaye kulula ukufunxa ukufuma.
(1) I-Hydroxyethyl cellulose iyanyibilika emanzini abandayo, kodwa kunzima ukuyinyibilika emanzini ashushu. Isisombululo saso sizinzile kwiqondo lokushisa eliphezulu ngaphandle kwe-gelling. Ingasetyenziselwa ixesha elide phantsi kobushushu obuphezulu kwidaka, kodwa ukugcinwa kwamanzi kwayo kuphantsi kune-methyl cellulose.
(2) I-Hydroxyethyl cellulose izinzile kwi-asidi ngokubanzi kunye ne-alkali. I-alkali inokukhawulezisa ukuchithwa kwayo kwaye inyuse kancinci i-viscosity yayo. I-dispersibility yayo emanzini imbi kancinane kune-methyl cellulose kunye ne-hydroxypropyl methyl cellulose. .
(3) I-Hydroxyethyl cellulose inokusebenza kakuhle kwe-anti-sag yodaka, kodwa inexesha elide lokubuyiswa kwesamente.
(4) Ukusebenza kwe-hydroxyethyl cellulose eveliswa ngamanye amashishini asekhaya isezantsi kakhulu kune-methyl cellulose ngenxa yomthamo wamanzi aphezulu kunye nothuthu oluphezulu.
4. I-Carboxymethyl cellulose (CMC):
I-Ionic cellulose ether yenziwe kwimicu yendalo (ikotoni, njl.njl.) emva konyango lwe-alkali, kusetyenziswa i-sodium monochloroacetate njenge-etherification agent, kwaye iphantsi koluhlu lwezonyango zokusabela. Iqondo lokutshintshwa ngokubanzi yi-0.4 ~ 1.4, kwaye ukusebenza kwayo kuchatshazelwa kakhulu ngumgangatho wokutshintshwa.
(1) I-Carboxymethyl cellulose i-hygroscopic ngakumbi, kwaye iya kuba namanzi amaninzi xa igcinwe phantsi kweemeko eziqhelekileyo.
(2) I-Carboxymethyl cellulose isisombululo samanzi asiyi kuvelisa i-gel, kwaye i-viscosity iya kuncipha ngokunyuka kweqondo lokushisa. Xa iqondo lokushisa lidlula i-50 ° C, i-viscosity ayinakuguqulwa.
(3) Ukuzinza kwayo kuchaphazeleka kakhulu yi-PH. Ngokuqhelekileyo, inokusetyenziswa kwi-gypsum-based mortar, kodwa kungekhona kwi-samente-based mortar. Xa i-alkaline iphezulu, iya kulahlekelwa yi-viscosity.
(4) Ugcino lwawo lwamanzi lungaphantsi kakhulu kunolo lwemethyl cellulose. Unempembelelo ephazamisayo kwi-gypsum-based mortar kwaye inciphisa amandla ayo. Nangona kunjalo, ixabiso le-carboxymethyl cellulose liphantsi kakhulu kunelo le-methyl cellulose.
Ixesha lokuposa: Feb-27-2023