I-cellulose ether odakeni oluxubile olulungile

Indima ebalulekile ye-cellulose ether odakeni oluxubile olulungile:

Odakeni oluxutshwe ngomumo, inani elengeziwe le-cellulose ether liphansi kakhulu, kodwa lingathuthukisa kakhulu ukusebenza kodaka olumanzi, ukusebenza kokwakhiwa kodaka kuyisengezo esikhulu.Ukukhetha okunengqondo kwezinhlobonhlobo ezahlukene, i-viscosity ehlukene, usayizi wezinhlayiyana ezahlukene, i-viscosity degree ehlukene kanye nokwengeza inani le-cellulose ether

Odakeni oluxutshwe ngomumo, inani elengeziwe le-cellulose ether liphansi kakhulu, kodwa lingathuthukisa kakhulu ukusebenza kodaka olumanzi, ukusebenza kokwakhiwa kodaka kuyisengezo esikhulu.Ukukhethwa okunengqondo kwe-cellulose ether enezinhlobonhlobo ezahlukene, i-viscosity ehlukene, ubukhulu bezinhlayiyana ezahlukene, i-viscosity degree ehlukene kanye nenani lokwengeza kunomphumela omuhle ekuthuthukiseni izakhiwo zodaka olomile.Njengamanje, udaka oluningi lwamatshe kanye nodaka lunokungasebenzi kahle kokugcinwa kwamanzi, futhi ukuhlukaniswa kodaka lwamanzi kuzokwenzeka ngemva kwemizuzu embalwa yokuma.

Ukugcinwa kwamanzi kuwumsebenzi obalulekile we-methyl cellulose ether, kodwa futhi nabakhiqizi abaningi basekhaya bodaka olomile, ikakhulukazi endaweni eseningizimu yabakhiqizi bokushisa okuphezulu abakhathazekile ngokusebenza.Izici ezithinta umphumela wokugcina amanzi wodaka olomile zifaka inani le-MC, i-MC viscosity, ubuhle bezinhlayiyana kanye nezinga lokushisa elizungezile.

I-Cellulose ether iyi-polymer yokwenziwa eyenziwe nge-cellulose yemvelo njengempahla eluhlaza ngokuguqulwa kwamakhemikhali.I-Cellulose ether iphuma ku-cellulose yemvelo, ukukhiqizwa kwe-cellulose ether kanye ne-polymer yokwenziwa kwehlukile, impahla yayo eyisisekelo i-cellulose, izinhlanganisela ze-polymer zemvelo.Ngenxa yemininingwane yesakhiwo se-cellulose yemvelo, i-cellulose ngokwayo ayinawo amandla okusabela nge-ejenti etherifying.Kodwa-ke, ngemva kokwelashwa kwe-ejenti yokuvuvukala, izibopho eziqinile ze-hydrogen phakathi kwamaketanga amangqamuzana nangaphakathi kweketanga zabhujiswa, futhi umsebenzi weqembu le-hydroxyl wakhululwa ku-alkali cellulose ngekhono lokuphendula, kanye ne-cellulose ether yatholakala ngokusabela kwe-ETHERifying agent - OH iqembu ku -NOMA iqembu.

Izici zama-cellulose ethers zincike ohlotsheni, inombolo kanye nokusatshalaliswa kwama-substituents.Ukuhlukaniswa kwe-cellulose ether kusekelwe futhi ohlotsheni lwezinye izingxenye, izinga le-etherification, ukunyibilika kanye nokusetshenziswa okuhlobene kungahlukaniswa.Ngokohlobo lwama-substituent ochungechungeni lwemolekyuli, ingahlukaniswa ibe i-ether eyodwa ne-ether exutshiwe.I-MC ivamise ukusetshenziswa njenge-ether eyodwa, kuyilapho i-HPMC iyi-ether exubile.I-Methyl cellulose ether MC iyiyunithi yemvelo ye-cellulose glucose ku-hydroxyl methoxide ethathelwa indawo ifomula yesakhiwo somkhiqizo ethi [COH7O2 (OH) 3-H (OCH3) H] X, i-hydroxypropyl methyl cellulose ether HPMC iyiyunithi engxenyeni ye-hydroxyl i-methoxide ithathelwa indawo i-hydroxypropyl, enye ingxenye yomkhiqizo ithathelwa indawo i-hydroxypropyl, Ifomula yesakhiwo ithi [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X kanye ne-hydroxyethyl methyl cellulose ether HEMC, esetshenziswa kakhulu futhi idayiswa emakethe.

Kusukela ku-solubility ingahlukaniswa ngohlobo lwe-ionic kanye nohlobo olungezona i-ionic.I-ether ye-cellulose engeyona i-ionic encibilikayo emanzini yakhiwa ikakhulukazi i-alkyl ether kanye ne-hydroxyl alkyl ether yochungechunge olubili lwezinhlobo.I-Ionic CMC isetshenziswa kakhulu okokuhlanza okokwenziwa, izindwangu, ukuphrinta, ukudla kanye nokuxhashazwa kwe-petroleum.I-non-ionic MC, i-HPMC, i-HEMC nezinye ezisetshenziswa kakhulu ezintweni zokwakha, i-latex coatings, imithi, i-chemistry yansuku zonke nezinye izici.Njenge-ejenti yokuqina, i-ejenti yokugcina amanzi, i-stabilizer, i-dispersant, i-ejenti yokwakha ifilimu.

Ukugcinwa kwamanzi e-cellulose ether: ekukhiqizeni izinto zokwakha, ikakhulukazi udaka olomile, i-cellulose ether idlala indima engenakushintshwa, ikakhulukazi ekukhiqizeni udaka olukhethekile (udaka oluguquliwe), kodwa futhi luyingxenye ebalulekile.Indima ebalulekile ye-ether ye-cellulose encibilikayo emanzini ikakhulukazi inezici ezintathu, eyodwa ikhono elihle kakhulu lokugcina amanzi, okwesibili ithonya lokungaguquguquki kodaka kanye ne-thixotropy, kanti okwesithathu ukuxhumana nosimende.Ukugcinwa kwamanzi e-cellulose ether, kuncike esisekelweni se-hydroscopicity, ukwakheka kodaka, ugqinsi lwengqimba yodaka, isidingo samanzi odaka, isikhathi sokufingqa sento yokufingqa.Ukugcinwa kwamanzi kwe-cellulose ether kuvela ekuncibilikeni nasekuphelelweni kwamanzi emzimbeni kwe-cellulose ether ngokwayo.Kuyaziwa ukuthi amaketanga e-cellulose yamangqamuzana, nakuba aqukethe inani elikhulu lamaqembu e-OH ane-hydrated kakhulu, awancibiliki emanzini ngenxa yesakhiwo sawo esicwebezelayo.Amandla okukhipha amanzi emaqenjini e-hydroxyl ewodwa akwanele ukukhokhela amabhondi e-hydrogen e-intermolecular aqinile namandla e-van der Waals.Lapho okushintshiwe kwethulwa ochungechungeni lwamangqamuzana, akuzona kuphela ezinye ezibhubhisa iketango le-hydrogen, kodwa futhi amabhondi e-hydrogen e-interchain ayaphulwa ngenxa yokugaxana kwezakhi phakathi kwamaketanga aseduze.Uma ama-substituent emakhulu, ibanga eliphakathi kwama-molecule likhulu.Ukubhujiswa okukhulu komphumela we-hydrogen bond, ukunwetshwa kwe-cellulose lattice, isixazululo ku-ether cellulose siba encibilikayo emanzini, ukwakheka kwesisombululo se-viscosity ephezulu.Njengoba izinga lokushisa likhuphuka, i-hydration ye-polymer iyancipha futhi amanzi phakathi kwamaketanga akhishwe.Lapho umphumela wokukhipha amanzi emzimbeni wanele, ama-molecule aqala ukuhlangana futhi ijeli igoqeka kunethiwekhi ye-three-dimensional.

Izici ezithinta ukugcinwa kwamanzi kodaka zihlanganisa i-cellulose ether viscosity, umthamo, ukuqina kwezinhlayiyana kanye nezinga lokushisa lesevisi.

Uma kukhulu i-viscosity ye-cellulose ether, kuba ngcono ukusebenza kokugcinwa kwamanzi.I-Viscosity iyipharamitha ebalulekile yokusebenza kwe-MC.Njengamanje, abakhiqizi abahlukene be-MC basebenzisa izindlela ezahlukene namathuluzi ukukala i-viscosity ye-MC.Izindlela eziyinhloko zihlanganisa i-Haake Rotovisko, i-Hoppler, i-Ubbelohde ne-Brookfield.Ngomkhiqizo ofanayo, imiphumela ye-viscosity elinganiswa ngezindlela ezahlukene ihluke kakhulu, eminye ihluke kakhulu.Ngakho-ke, uma uqhathanisa i-viscosity, kufanele yenziwe phakathi kwendlela yokuhlola efanayo, kufaka phakathi izinga lokushisa, i-rotor, njll.

Ngokuvamile, ukuphakama kwe-viscosity, kuba ngcono umphumela wokugcina amanzi.Kodwa-ke, lapho i-viscosity iphezulu, isisindo se-molecule ye-MC siphezulu, futhi ukusebenza kokuhlakazeka kuzokwehla ngokuhambisanayo, okunomthelela omubi emandleni nasekusebenzeni kokwakhiwa kodaka.Ukuphakama kwe-viscosity, umphumela wokujiya we-mortar ubonakala, kodwa awulingani nobuhlobo.Ukuphakama kwe-viscosity, udaka olumanzi luyoba lunamathele kakhulu, kokubili ukwakhiwa, ukusebenza kwe-scraper enamathelayo kanye nokunamathela okuphezulu kwesisekelo.Kodwa akusizi ukwandisa amandla esakhiwo sodaka olumanzi.Ngesikhathi sokwakhiwa, ukusebenza kwe-anti-sag akubonakali.Ngokuphambene, i-viscosity ethile ephansi kodwa i-methyl cellulose ether eshintshiwe inokusebenza okuhle kakhulu ekuthuthukiseni amandla esakhiwo sodaka olumanzi.

Uma i-cellulose ether ingeziwe odakeni, ukusebenza okungcono kokugcinwa kwamanzi, ukuphakama kwe-viscosity, ukusebenza okungcono kokugcinwa kwamanzi.

Ngosayizi wezinhlayiyana, ukucoleka kwezinhlayiyana, kuba ngcono nokugcinwa kwamanzi.Izinhlayiya ezinkulu ze-cellulose ether ezithintana namanzi, indawo engaphezulu iyancibilika ngokushesha futhi yakha ijeli ukugoqa izinto ukuvimbela ama-molecule amanzi ukuthi aqhubeke nokungena, ngezinye izikhathi isikhathi eside esinyakazayo asikwazi ukuhlakazwa ngokulinganayo, ukwakheka kwesisombululo esinodaka noma i-flocculent solution. i-agglomerate.Ukunyibilika kwe-cellulose ether kungenye yezinto zokukhetha i-cellulose ether.I-Fineness futhi iyinkomba yokusebenza ebalulekile ye-methyl cellulose ether.I-MC yodaka olomile idinga impushana, okuqukethwe kwamanzi aphansi, nokucoleka kuka-20% ~ 60% usayizi wezinhlayiyana ngaphansi kuka-63um.Ubuhle buthinta ukunyibilika kwe-methyl cellulose ether.I-coarse MC ivamise ukuba yi-granular futhi ingancibilika kalula emanzini ngaphandle kwe-agglomerating, kodwa isivinini sokuhlakazeka sihamba kancane, ngakho-ke ayifanele ukusetshenziswa odakeni olomile.Odakeni olomile, i-MC ihlakazwa phakathi kwe-aggregate, izigcwalisi ezinhle nezinto zikasimende ezifana nosimende, futhi impushana kuphela ekahle ngokwanele engagwema ukunqwabelana kwe-methyl cellulose ether lapho ixutshwa namanzi.Lapho i-MC ingeza amanzi ukuncibilikisa i-agglomerate, kunzima kakhulu ukuyihlakaza nokuyincibilikisa.I-MC ene-coarse fineness ayigcini nje ngokumosha, kodwa futhi inciphisa amandla endawo yodaka.Uma udaka olomile olunjalo lwakhiwe endaweni enkulu, isivinini sokuphulukisa sodaka olomile lwendawo sincipha kakhulu, okuholela ekuqhekekeni okubangelwa isikhathi sokuphulukisa esihlukile.Ngodaka lokufafaza ngomshini, ngenxa yesikhathi esifushane sokuxuba, ubuhle buphakeme.

Ukucoleka kwe-MC nakho kunomthelela othile ekugcinweni kwayo kwamanzi.Ngokuvamile, ku-methyl cellulose ether ene-viscosity efanayo kodwa ukucoleka okuhlukile, umphumela wokugcina amanzi uba ngcono ngaphansi kwenani elifanayo lokungezwa.

Ukugcinwa kwamanzi kwe-MC nakho kuhlobene nezinga lokushisa elisetshenzisiwe, futhi ukugcinwa kwamanzi kwe-methyl cellulose ether kuncipha ngokukhuphuka kwezinga lokushisa.Kodwa ekusetshenzisweni kwezinto ezibonakalayo, izindawo eziningi zodaka olomile ngokuvamile zizoba sezingeni lokushisa eliphezulu (ngaphezulu kwama-degrees angu-40) ngaphansi kwesimo sokwakhiwa endaweni eshisayo, njengokufakwa ehlobo kwe-putty plastering yangaphandle, evame ukusheshisa ukuqina kwe-substrate. usimende nodaka olomile ukuqina.Ukwehla kwezinga lokugcinwa kwamanzi kuholela emuzweni osobala wokuthi kokubili ukwakheka nokumelana nokuqhekeka kuyathinteka.Kulesi simo, ukunciphisa ithonya lezici lokushisa kuba okubaluleke kakhulu.Nakuba isithasiselo se-methyl hydroxyethyl cellulose ether sithathwa njengesihamba phambili ekuthuthukisweni kobuchwepheshe, ukuncika kwayo kumazinga okushisa kusazoholela ekwenziweni buthaka kwezakhiwo zodaka olomile.Ngisho nokwenyuka komthamo we-methyl hydroxyethyl cellulose (ifomula yasehlobo), ukumelana nokwakhiwa nokuqhekeka akukakwazi ukuhlangabezana nezidingo zokusetshenziswa.Ngokwelashwa okuthile okukhethekile kwe-MC, njengokwandisa izinga lokufakwa kwe-etherification, umphumela wokugcina amanzi we-MC ungagcina umphumela ongcono ngaphansi kwezinga lokushisa eliphezulu, ukuze ukwazi ukunikeza ukusebenza okungcono ngaphansi kwezimo ezinzima.

Ngaphezu kwalokho, i-cellulose ether thickening kanye ne-thixotropy: isenzo sesibili se-cellulose ether - ukuqina kuncike: i-cellulose ether polymerization degree, ukuhlushwa kwesisombululo, izinga le-shear, izinga lokushisa nezinye izimo.Impahla ye-gelation yesisombululo ihlukile ku-alkyl cellulose kanye nokuphuma kwayo okuguquliwe.Izici ze-Gelation zihlobene nezinga lokushintshwa, ukugxila kwesisombululo kanye nezithasiselo.Kokuphuma kokunye okuguquliwe kwe-hydroxyl alkyl, izakhiwo zejeli nazo zihlobene nezinga lokuguqulwa kwe-hydroxyl alkyl.Ukuze uthole ukuhlushwa kwesisombululo se-viscosity ephansi ye-MC ne-HPMC ingalungiswa i-10% -15% isixazululo sokuhlushwa, i-viscosity ephakathi kwe-MC ne-HPMC ingalungiswa isixazululo esingu-5% -10%, futhi i-viscosity ephezulu ye-MC ne-HPMC ingalungiswa kuphela 2% -3 % isisombululo, futhi ngokuvamile i-cellulose ether viscosity grading ibuye ibe yisixazululo esingu-1% -2% sebanga.Isisindo esiphezulu se-cellulose ether thickener ukusebenza kahle, ukuhlushwa okufanayo kwesisombululo, ama-polymers esisindo samangqamuzana ahlukene ane-viscosity ehlukene, i-viscosity nesisindo samangqamuzana kungavezwa kanje, [η]=2.92×10-2 (DPn) 0.905, i-DPn isilinganiso i-polymerization degree ephezulu.Isisindo esiphansi se-cellulose ether ukwengeza okwengeziwe ukuze kuzuzwe i-viscosity ehlosiwe.I-viscosity yayo ayincikile kangako ku-shear rate, i-viscosity ephezulu ukufeza i-viscosity ehlosiwe, inani elidingekayo ukuze wengeze kancane, i-viscosity incike ekusebenzeni kahle kokuqina.Ngakho-ke, ukuze kuzuzwe ukuvumelana okuthile, inani elithile le-cellulose ether (ukugxila kwesisombululo) kanye ne-viscosity yesisombululo kufanele kuqinisekiswe.Izinga lokushisa le-gelation lesisombululo liye lancipha ngokuhambisana nokwanda kokugxila kwesisombululo, futhi i-gelation yenzeke ekamelweni lokushisa ngemva kokufinyelela ekugxilweni okuthile.I-HPMC inokugxilwa kwe-gelation okuphezulu ekamelweni lokushisa.

Ukuvumelana kungabuye kulungiswe ngokukhetha usayizi wezinhlayiyana nama-cellulose ether anamazinga ahlukene okuguqulwa.Okubizwa ngokuthi ukuguqulwa ukwethulwa kweqembu le-hydroxyl alkyl ngezinga elithile lokushintsha esakhiweni samathambo e-MC.Ngokushintsha amanani ashintshile ahlobene ezinto ezimbili ezibambele, okungukuthi, amanani ashintshile ahlobene we-DS ne-MS weqembu le-methoxy ne-hydroxyl.Izakhiwo ezihlukahlukene ze-cellulose ether ziyadingeka ngokushintsha amanani ashintshile ahlobene ezinhlobo ezimbili zama-substitutes.

Ubudlelwano phakathi kokuvumelana nokuguqulwa: ukungezwa kwe-cellulose ether kuthinta ukusetshenziswa kwamanzi kodaka, futhi kushintsha isilinganiso se-water-binder samanzi nosimende, okuwumphumela wokuqina.Lapho umthamo uphakeme, ukusetshenziswa kwamanzi kuyanda.

Ama-cellulose ether asetshenziswa ezintweni zokwakha eziyimpuphu kufanele ahlakazeke ngokushesha emanzini abandayo futhi anikeze ukuhambisana okulungile ohlelweni.Uma izinga lokugunda elinikeziwe lisalokhu linyakaza futhi liyi-colloidal liwumkhiqizo osezingeni eliphansi noma wekhwalithi ephansi.

Kukhona futhi ubudlelwano obuhle bomugqa phakathi kokungaguquguquki kwe-slurry kasimende kanye nesilinganiso se-cellulose ether, i-cellulose ether ingakhuphula kakhulu i-viscosity yodaka, umthamo omkhulu, umphumela osobala kakhulu.Isixazululo samanzi se-cellulose ether esine-viscosity ephezulu sine-thixotropy ephezulu, okungenye yezici ze-cellulose ether.Izisombululo ezinamanzi zama-polymers ohlobo lwe-MC ngokuvamile zine-pseudoplastic, non-thixotropic fluidity ngaphansi kwezinga lokushisa lejeli, kodwa izakhiwo zokugeleza kwe-Newtonian ngamanani aphansi e-shear.I-Pseudoplasticity iyanda ngokukhula kwesisindo sengqamuzana noma ukugcwala kwe-cellulose ether futhi izimele ohlotsheni oluhlukile neziqu.Ngakho-ke, ama-cellulose ethers webanga elifanayo le-viscosity, kungakhathaliseki ukuthi i-MC, i-HPMC noma i-HEMC, ahlala ebonisa izici ezifanayo ze-rheological inqobo nje uma ukugxila nokushisa kuhlala njalo.Lapho izinga lokushisa likhuphuka, i-gel yesakhiwo iyakhiwa futhi ukugeleza okuphezulu kwe-thixotropic kwenzeka.Ama-cellulose ethers ane-concentration ephezulu kanye ne-viscosity ephansi abonisa i-thixotropy ngisho nangaphansi kwezinga lokushisa lejeli.Lesi sakhiwo sinenzuzo enkulu ekwakhiweni kodaka lwesakhiwo ukulungisa ukugeleza nokugeleza kwendawo elengayo.Kudingeka kuchazwe lapha ukuthi ukuphakama kwe-viscosity ye-cellulose ether, kungcono ukugcina amanzi, kodwa ukuphakama kwe-viscosity, ukuphakama kwesisindo se-cellulose ether, ukuncipha okuhambisanayo kokuncibilika kwayo, okunomthelela omubi ukugxila kodaka nokusebenza kokwakhiwa.Ukuphakama kwe-viscosity, kusobala kakhulu umphumela wokujiya wodaka, kodwa akuwona ubudlelwano obuphelele bokulinganisa.I-viscosity ethile ephansi, kodwa i-cellulose ether eguquliwe ekuthuthukiseni amandla esakhiwo sodaka olumanzi inokusebenza okuhle kakhulu, ngokunyuka kwe-viscosity, ukugcinwa kwamanzi kwe-cellulose ether kuyathuthukiswa.

I-cellulose ether retardation: i-cellulose ether indima yesithathu iwukubambezela inqubo yokugeleza kukasimende.I-cellulose ether inika udaka olunezinto ezihlukahlukene ezizuzisayo, kodwa futhi yehlisa ukukhululwa kokushisa kwe-hydration ekuqaleni kukasimende, ibambezela inqubo ye-hydration ashukumisayo kasimende.Lokhu akulungile ukusetshenziswa kodaka ezindaweni ezibandayo.Lolu hlobo lomphumela wokuhlehlisa i-cellulose ether molecule adsorption ku-CSH kanye ne-Ca (OH) 2 imikhiqizo ye-hydration ebangelwa, ngenxa yokwanda kwe-viscosity yesisombululo se-pore, i-cellulose ether inciphisa umsebenzi we-ion kusixazululo, ngaleyo ndlela ibambezele inqubo ye-hydration.Ukuphakama kokugcwala kwe-cellulose ether kujeli yamaminerali, kuba sobala kakhulu umthelela wokulibaziseka kwe-hydration.I-cellulose ether ayilibazisi nje kuphela ukulungiselelwa, kodwa futhi nenqubo yokuqina yesistimu yodaka lukasimende.Umphumela wokuvinjelwa kwe-cellulose ether awuncikile kuphela ekugxilweni kwayo ohlelweni lwejeli yamaminerali, kodwa futhi nesakhiwo samakhemikhali.Ukuphakama kwedigri ye-HEMC methylation, kuba ngcono umphumela wokuvinjelwa kwe-cellulose ether.Umphumela wokuvinjelwa kokushintshwa kwe-hydrophilic unamandla kunalowo wokushintsha okwandisa amanzi.Kodwa i-viscosity ye-cellulose ether inethonya elincane ku-hydration kinetics kasimende.

Ngokukhula kokuqukethwe kwe-cellulose ether, isikhathi sokusetha sodaka sikhula kakhulu.Isikhathi sokuqala sokusetha sodaka sinokuhlobana okuhle komugqa nokuqukethwe kwe-cellulose ether, futhi isikhathi sokugcina sokusetha sinokuhlobana okuhle komugqa nokuqukethwe kwe-cellulose ether.Singalawula isikhathi sokusebenza sodaka ngokushintsha umthamo we-cellulose ether.

Ukufingqa, ngodaka oluxubekile, i-cellulose ether idlala indima ekugcineni amanzi, ukuqina, ukubambezeleka kwamandla kasimende, ukuthuthukisa ukusebenza kokwakhiwa.Amandla amahle okugcina amanzi enza usimende hydration iphelele kakhudlwana, ingathuthukisa i-viscosity emanzi yodaka olumanzi, ithuthukise amandla okubopha odaka, isikhathi esilungisekayo.Ukwengeza i-cellulose ether kudaka lokufafaza lomshini kungathuthukisa ukusebenza kokufutha noma ukumpompa namandla esakhiwo sodaka.Ngakho-ke, i-cellulose ether isetshenziswa kabanzi njengesengezo esibalulekile odakeni oluxutshwe ngomumo.