Ngodaka oluhlanganisiwe, inani elingeziwe le-cellulose ether liphansi kakhulu, kodwa lingathuthukisa kakhulu ukusebenza kodaka olumanzi, futhi liyisithasiselo esiyinhloko esithinta ukusebenza kokwakhiwa kodaka. Ukukhethwa okunengqondo kwama-cellulose ethers ezinhlobonhlobo ezahlukene, ama-viscosity ahlukene, ubukhulu bezinhlayiya ezihlukahlukene, amazinga ahlukene e-viscosity namanani angeziwe azoba nomthelela omuhle ekuthuthukiseni ukusebenza kwe-powder mortar. Njengamanje, ama-masonry amaningi kanye ne-plastering mortars anokusebenza kahle kokugcina amanzi, futhi udaka lwamanzi luzohlukana ngemva kwemizuzu embalwa yokuma. Ukugcinwa kwamanzi kuwumsebenzi obalulekile we-methyl cellulose ether, futhi kuwumsebenzi abakhiqizi abaningi basekhaya bengxube eyomile yodaka, ikakhulukazi labo abasezifundeni eziseningizimu enamazinga okushisa aphezulu, banake. Izinto ezithinta umphumela wokugcina amanzi wodaka lwengxube eyomile zihlanganisa inani le-MC elingeziwe, i-viscosity ye-MC, ukucoleka kwezinhlayiya kanye nezinga lokushisa lendawo yokusetshenziswa.
1. Umqondo
I-Cellulose ether iyi-polymer yokwenziwa eyenziwe nge-cellulose yemvelo ngokuguqulwa kwamakhemikhali. I-Cellulose ether iphuma ku-cellulose yemvelo. Ukukhiqizwa kwe-cellulose ether kuhlukile kuma-polymers okwenziwa. Impahla yayo eyisisekelo i-cellulose, isakhi se-polymer yemvelo. Ngenxa yemininingwane yesakhiwo se-cellulose yemvelo, i-cellulose ngokwayo ayinalo ikhono lokusabela nge-etherification agents. Kodwa-ke, ngemva kokwelashwa kwe-ejenti yokuvuvukala, izibopho eziqinile ze-hydrogen phakathi kwamaketanga amangqamuzana namaketanga ziyabhujiswa, futhi ukukhululwa okusebenzayo kweqembu le-hydroxyl kuba i-alkali cellulose esebenzayo. Thola i-cellulose ether.
Izici zama-cellulose ethers zincike ohlotsheni, inombolo nokusatshalaliswa kwezinto ezibambele. Ukuhlukaniswa kwe-cellulose ethers futhi kusekelwe ohlotsheni lwama-substitute, izinga le-etherification, ukuncibilika kanye nezakhiwo zesicelo ezihlobene. Ngokuya kohlobo lwama-substituent ochungechungeni lwemolekyuli, ingahlukaniswa ibe i-monoether ne-ether exutshiwe. I-MC esivame ukuyisebenzisa i-monoether, futhi i-HPMC iyi-ether exubile. I-Methyl cellulose ether MC iwumkhiqizo ngemuva kokuthi iqembu le-hydroxyl kuyunithi ye-glucose ye-cellulose yemvelo lithathelwe indawo yi-methoxy. Kungumkhiqizo otholwe ngokufaka esikhundleni ingxenye yeqembu le-hydroxyl kuyunithi neqembu le-methoxy kanye nengxenye neqembu le-hydroxypropyl. Ifomula yesakhiwo ithi [C6H7O2(OH)3-mn(OCH3)m[OCH2CH(OH)CH3]n]x Hydroxyethyl methyl cellulose ether HEMC, lezi yizinhlobo eziyinhloko ezisetshenziswa kakhulu futhi ezithengiswa emakethe.
Ngokuya nge-solubility, ingahlukaniswa ibe yi-ionic ne-non-ionic. Ama-ether e-non-ionic cellulose ancibilika emanzini akhiwa ikakhulukazi uchungechunge olubili lwama-alkyl ether kanye nama-hydroxyalkyl ether. I-Ionic CMC isetshenziswa kakhulu ezintweni zokwenziwa zokuhlanza, ukuphrinta izindwangu nokudaya, ukuhlola ukudla nowoyela. I-Non-ionic MC, i-HPMC, i-HEMC, njll. isetshenziswa ikakhulukazi ezintweni zokwakha, i-latex coatings, imithi, amakhemikhali ansuku zonke, njll. Isetshenziswa njenge-thickener, i-ejenti yokugcina amanzi, i-stabilizer, i-disperant kanye ne-ejenti eyenza ifilimu.
Okwesibili, ukugcinwa kwamanzi kwe-cellulose ether
Ukugcinwa kwamanzi kwe-cellulose ether: Ekukhiqizeni izinto zokwakha, ikakhulukazi udaka lwempuphu eyomile, i-cellulose ether idlala indima engenakushintshwa, ikakhulukazi ekukhiqizeni udaka olukhethekile (udaka oluguquliwe), luyingxenye ebalulekile futhi ebalulekile .
Indima ebalulekile ye-ether ye-cellulose encibilikayo emanzini ikakhulukazi inezici ezintathu, eyodwa iwumthamo omuhle kakhulu wokugcinwa kwamanzi, enye ithonya lokungaguquguquki kanye ne-thixotropy yodaka, kanti okwesithathu ukuxhumana nosimende. Umphumela wokugcina amanzi we-cellulose ether uncike ekumunceni kwamanzi kwesendlalelo sesisekelo, ukwakheka kodaka, ukujiya kongqimba lodaka, isidingo samanzi sodaka, kanye nesikhathi sokusetha sendawo yokusetha. Ukugcinwa kwamanzi kwe-cellulose ether ngokwayo kuvela ekuncibilikeni nasekuphelelweni kwamanzi emzimbeni kwe-cellulose ether ngokwayo. Njengoba sonke sazi, nakuba iketanga lamangqamuzana e-cellulose liqukethe inani elikhulu lamaqembu e-OH ane-hydratable, ayincibiliki emanzini, ngoba isakhiwo se-cellulose sinezinga eliphezulu le-crystallinity.
Amandla okukhipha amanzi emaqenjini e-hydroxyl ewodwa akwanele ukumboza amabhondi e-hydrogen aqinile namandla e-van der Waals phakathi kwama-molecule. Ngakho-ke, iyakhukhumala kuphela kodwa ayincibiliki emanzini. Lapho enye indawo yethulwa ochungechungeni lwamangqamuzana, akugcini nje kuphela ukuthi okungene esikhundleni kucekela phansi iketango le-hydrogen, kodwa futhi isibopho se-hydrogen se-interchain siyabhujiswa ngenxa yokuhlangana kwento ebambele phakathi kwamaketanga aseduze. Uma i-substitute inkulu, ibanga eliphakathi kwama-molecule liba likhulu. Ibanga elikhulu. Umphumela omkhulu wokucekela phansi izibopho ze-hydrogen, i-cellulose ether iyancibilika emanzini ngemva kokuba i-cellulose lattice yanda futhi isisombululo singena, sakha isisombululo se-viscosity ephezulu. Lapho izinga lokushisa likhuphuka, i-hydration ye-polymer iba buthaka, futhi amanzi phakathi kwamaketanga axoshwa. Lapho umphumela wokuphelelwa amanzi emzimbeni wanele, ama-molecule aqala ukuhlanganisa, enze ijeli yesakhiwo senethiwekhi enezinhlangothi ezintathu futhi ahlanganiswe.
Izinto ezithinta ukugcinwa kwamanzi kodaka zihlanganisa i-cellulose ether viscosity, inani elingeziwe, ukucoleka kwezinhlayiyana nezinga lokushisa lokusebenzisa:
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 namathuluzi ahlukene ukukala i-viscosity ye-MC. Izindlela eziyinhloko yi-Haake Rotovisko, i-Hoppler, i-Ubbelohde ne-Brookfield. Ngomkhiqizo ofanayo, imiphumela ye-viscosity elinganiswa ngezindlela ezahlukene ihluke kakhulu, futhi eminye inomehluko ophindwe kabili. Ngakho-ke, lapho uqhathanisa i-viscosity, kufanele yenziwe phakathi kwezindlela ezifanayo zokuhlola, kufaka phakathi izinga lokushisa, i-rotor, njll.
Ngokuvamile, ukuphakama kwe-viscosity, kuba ngcono umphumela wokugcina amanzi. Kodwa-ke, ukuphakama kwe-viscosity futhi ukuphakama kwesisindo samangqamuzana e-MC, ukwehla okuhambisanayo kokuncibilika kwawo kuzoba nomthelela omubi emandleni nokusebenza kokwakhiwa kodaka. Ukuphakama kwe-viscosity, kusobala kakhulu umphumela wokuqina odongeni, kodwa awulingani ngokuqondile. Ukuphakama kwe-viscosity, i-viscous yodaka olumanzi luyoba ngaphezulu, okungukuthi, ngesikhathi sokwakhiwa, kubonakala njengokunamathela ku-scraper nokunamathela okuphezulu ku-substrate. Kodwa akusizi ukwandisa amandla esakhiwo sodaka olumanzi ngokwalo. Ngesikhathi sokwakhiwa, ukusebenza kwe-anti-sag akubonakali. Ngokuphambene, i-viscosity ethile emaphakathi nephansi kodwa eshintshiwe ye-methyl cellulose ethers inokusebenza okuhle kakhulu ekuthuthukiseni amandla esakhiwo sodaka olumanzi.
Uma sikhulu inani le-cellulose ether engezwe odakeni, ngcono ukusebenza kokugcinwa kwamanzi, futhi lapho ukuphakama kwe-viscosity, kuba ngcono ukusebenza kokugcinwa kwamanzi.
Mayelana nosayizi wezinhlayiyana, ukucoleka kwezinhlayiyana, kuba ngcono nokugcinwa kwamanzi. Ngemva kokuba izinhlayiya ezinkulu ze-cellulose ether zihlangana namanzi, indawo engaphezulu iyancibilika ngokushesha futhi yakhe ijeli ukuze igoqe into ukuvimbela ama-molecule amanzi ukuthi angaqhubeki nokungena. Ngezinye izikhathi ayikwazi ukuhlakazwa ngokufanayo futhi incibilike ngisho nangemva kokunyakaziswa kwesikhathi eside, kwakheka ikhambi eliguqubele le-flocculent noma i-agglomeration. Kuthinta kakhulu ukugcinwa kwamanzi kwe-cellulose ether, futhi ukuncibilika kungenye yezici zokukhetha i-cellulose ether.
I-Fineness futhi iyinkomba yokusebenza ebalulekile ye-methyl cellulose ether. I-MC esetshenziselwa udaka lwempushana eyomile iyadingeka ukuthi ibe yimpushana, enokuqukethwe kwamanzi aphansi, kanti ukucoleka kudinga u-20% ~ 60% wesayizi wezinhlayiyana ukuba ube ngaphansi kuka-63um. Ukucoleka kuthinta ukunyibilika kwe-methyl cellulose ether. I-coarse MC ivamise ukuba yi-granular, futhi kulula ukuyincibilika emanzini ngaphandle kwe-agglomeration, kodwa izinga lokuhlakazeka lihamba kancane, ngakho-ke alifanelekile ukusetshenziswa kudaka oluyimpushana. Odakeni lwempushana eyomile, i-MC ihlakazeka phakathi kwezinto zikasimende njenge-aggregate, isigcwalisi esihle nosimende, futhi impushana enhle kuphela eyanele engagwema i-methyl cellulose ether agglomeration lapho ixutshwa namanzi. Lapho i-MC yengezwe ngamanzi ukuze ihlakaze ama-agglomerate, kunzima kakhulu ukuhlakazeka nokuhlakazeka.
Ukucoleka kwe-MC akukona nje ukumosha, kodwa futhi kunciphisa amandla endawo odaka. Uma i-powder mortar enjalo eyomile isetshenziswa endaweni enkulu, ijubane lokuphulukisa le-powder eyomile yendawo lizoncishiswa kakhulu, futhi imifantu izovela ngenxa yezikhathi ezahlukene zokuphulukisa. Ngodaka olufuthwe ngokwakhiwa kwemishini, imfuneko yokucwenga iphakeme ngenxa yesikhathi esifushane sokuxuba.
Ukucoleka kwe-MC nakho kunomthelela othile ekugcineni kwayo amanzi. Ngokuvamile, kuma-methyl cellulose ether ane-viscosity efanayo kodwa ukucoleka okuhlukile, ngaphansi kwesamba esifanayo sokwengezwa, ukucoleka kuya kuba ngcono umphumela wokugcina amanzi.
Ukugcinwa kwamanzi kwe-MC nakho kuhlobene nezinga lokushisa elisetshenzisiwe, futhi ukugcinwa kwamanzi kwe-methyl cellulose ether kuncipha ngokunyuka kwezinga lokushisa. Kodwa-ke, ekusetshenzisweni kwezinto ezibonakalayo, udaka oluyimpushana olomile luvame ukusetshenziswa ezindaweni ezishisayo emazingeni okushisa aphezulu (angaphezu kwama-degrees angu-40) ezindaweni eziningi, njengokuphahlelwa kwe-putty yangaphandle ngaphansi kwelanga ehlobo, okuvame ukusheshisa Ukuphulukiswa kukasimende nokuqina kukasimende. udaka olomile lwempuphu. Ukwehla kwezinga lokugcinwa kwamanzi kuholela emuzweni osobala wokuthi kokubili ukusebenza nokumelana nokuqhekeka kuyathinteka, futhi kubaluleke kakhulu ukunciphisa umthelela wezici zokushisa ngaphansi kwalesi simo.
Nakuba izithasiselo ze-methyl hydroxyethyl cellulose ether njengamanje zibhekwa njengezihamba phambili ekuthuthukisweni kwezobuchwepheshe, ukuncika kwazo ekushiseni kusazoholela ekwenzeni buthaka ukusebenza kwe-powder mortar. Nakuba inani le-methyl hydroxyethyl cellulose linyusiwe (ifomula yasehlobo), ukusebenza kahle nokumelana nokuqhekeka akukakwazi ukuhlangabezana nezidingo zokusetshenziswa. Ngokuphathwa okuthile okukhethekile ku-MC, njengokwandisa izinga le-etherification, njll., umphumela wokugcina amanzi ungagcinwa ezingeni lokushisa eliphezulu, ukuze ukwazi ukunikeza ukusebenza okungcono ngaphansi kwezimo ezinzima.
3. Ukuqina kanye Thixotropy yeCellulose Ether
Ukuqina kanye ne-thixotropy ye-cellulose ether: Umsebenzi wesibili we-cellulose ether-ukuqina komphumela uncike: izinga le-polymerization ye-cellulose ether, ukuhlushwa kwesisombululo, izinga le-shear, izinga lokushisa nezinye izimo. Impahla ye-gelling yesisombululo ihlukile ku-alkyl cellulose kanye nokuphuma kwayo okuguquliwe. Izakhiwo ze-gelation zihlobene nezinga lokushintshwa, ukugxila kwesisombululo kanye nezithasiselo. Kokuphuma kokunye okuguquliwe kwe-hydroxyalkyl, izakhiwo zejeli nazo zihlobene nezinga lokuguqulwa le-hydroxyalkyl. Ukuze uthole i-viscosity ephansi ye-MC ne-HPMC, isisombululo se-10% -15% singalungiswa, i-viscosity ephakathi kwe-MC ne-HPMC ingalungiswa isixazululo esingu-5% -10%, kuyilapho i-viscosity ephezulu ye-MC ne-HPMC ingalungisa kuphela isixazululo esingu-2% -3%, futhi Ngokuvamile ukuhlukaniswa kwe-viscosity ye-cellulose ether nayo ihlelwe ngesisombululo se-1% -2%.
I-high molecular weight cellulose ether ine-high thickening ukusebenza kahle. Esixazululweni esifanayo sokuhlushwa, ama-polymer anesisindo samangqamuzana ahlukene anama-viscosity ahlukene. Izinga eliphezulu. I-viscosity ehlosiwe ingafinyelelwa kuphela ngokungeza inani elikhulu lesisindo esiphansi se-cellulose ether. I-viscosity yayo inokwencika okuncane kuzinga lokugunda, futhi i-viscosity ephezulu ifinyelela i-viscosity ehlosiwe, futhi inani elidingekayo lokwengeza lincane, futhi 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 lejeli lesisombululo liphinde linciphise ngokuhambisana nokwanda kokuhlushwa kwesisombululo, nama-gel ekamelweni lokushisa ngemva kokufinyelela ekugxilweni okuthile. I-concentration ye-gelling ye-HPMC iphezulu uma kuqhathaniswa nezinga lokushisa legumbi.
Ukuvumelana kungabuye kulungiswe ngokukhetha usayizi wezinhlayiyana nokukhetha ama-cellulose ether anamazinga ahlukene okuguqulwa. Lokhu okubizwa ngokuthi ukuguqulwa ukwethula izinga elithile lokushintshwa kwamaqembu e-hydroxyalkyl esakhiweni samathambo e-MC. Ngokushintsha amanani ashintshile ahlobene ezinto ezimbili ezibambele, okungukuthi, i-DS kanye ne-ms amanani okushintsha ahlobene weqembu le-methoxy ne-hydroxyalkyl esivame ukukusho. Izidingo zokusebenza ezihlukahlukene ze-cellulose ether zingatholwa ngokushintsha amanani ashintshile ahlobene walezi zingxenye ezimbili.
Ubudlelwano phakathi kokuvumelana nokuguqulwa: ukungezwa kwe-cellulose ether kuthinta ukusetshenziswa kwamanzi kodaka, ukushintsha isilinganiso samanzi-isibopho samanzi kanye nosimende kuwumphumela wokuqina, ukuphakama komthamo, kukhulu ukusetshenziswa kwamanzi.
Ama-cellulose ethers asetshenziswa ezintweni zokwakha eziyimpuphu kufanele ahlakazeke ngokushesha emanzini abandayo futhi anikeze ukuhambisana okufanele kwesistimu. Uma inikezwa izinga elithile lokugunda, isala iphenduka i-flocculent futhi i-colloidal block, okuwumkhiqizo osezingeni eliphansi noma ompofu.
Kuphinde kube nobudlelwano obuhle bomugqa phakathi kokuvumelana kokunamathisela usimende kanye nomthamo we-cellulose ether. I-cellulose ether ingakhuphula kakhulu i-viscosity yodaka. Uma umthamo umkhulu, umphumela uba sobala kakhulu. Isixazululo samanzi se-cellulose ether se-high-viscosity sine-thixotropy ephezulu, okubuye kube isici esikhulu se-cellulose ether. Izixazululo ezinamanzi zama-polymers e-MC zivame ukuba ne-pseudoplastic kanye ne-non-thixotropic fluidity ngaphansi kwezinga lokushisa lejeli, kodwa izakhiwo zokugeleza kwe-Newtonian ngamanani aphansi e-shear. I-Pseudoplasticity iyanda ngesisindo se-molecular noma ukugxila kwe-cellulose ether, kungakhathaliseki ukuthi hlobo luni lwe-substitute kanye nezinga lokushintsha. Ngakho-ke, ama-cellulose ethers webanga elifanayo le-viscosity, kungakhathaliseki ukuthi i-MC, i-HPMC, i-HEMC, izohlale ibonisa izici ezifanayo ze-rheological inqobo nje uma ukugxila nokushisa kugcinwa njalo.
Ama-gel esakhiwo akhiwa lapho izinga lokushisa liphakanyiswa, futhi ukugeleza kwe-thixotropic kakhulu kwenzeka. I-concentration ephezulu kanye ne-viscosity ephansi ye-cellulose ethers ibonisa i-thixotropy ngisho nangaphansi kwezinga lokushisa le-gel. Lesi sakhiwo sinenzuzo enkulu ekulungisweni kokulinganisa nokuwohloka ekwakhiweni kodaka lokwakha. Kudingeka kuchazwe lapha ukuthi ukuphakama kwe-viscosity ye-cellulose ether, ukugcinwa kwamanzi kangcono, kodwa ukuphakama kwe-viscosity, ukuphakama kwesisindo samangqamuzana e-cellulose ether, kanye nokuncipha okuhambisanayo kokuncibilika kwayo, okunomthelela omubi. ekugxilweni kodaka nokusebenza kokwakhiwa. Ukuphakama kwe-viscosity, kusobala kakhulu umphumela wokuqina odongeni, kodwa awulingani ngokuphelele. I-viscosity ethile emaphakathi nephansi, kodwa i-cellulose ether eshintshiwe inokusebenza okungcono ekuthuthukiseni amandla esakhiwo sodaka olumanzi. Ngokukhula kwe-viscosity, ukugcinwa kwamanzi kwe-cellulose ether kuyathuthuka. 4. Ukuncipha kwe-cellulose ether
Ukuncipha kwe-cellulose ether: Umsebenzi wesithathu we-cellulose ether uwukubambezeleka kwenqubo yokugeleza kukasimende. I-cellulose ether inika udaka olunezinto ezihlukahlukene ezizuzisayo, futhi inciphisa ukushisa kwangaphambi kwesikhathi kwe-hydration kasimende futhi ibambezele inqubo ye-hydration ashukumisayo kasimende. Lokhu akulungile ukusetshenziswa kodaka ezindaweni ezibandayo. Lo mphumela wokuvinjelwa ubangelwa ukukhangisa kwama-molecule e-cellulose ether emikhiqizweni ye-hydration efana ne-CSH ne-ca(OH)2. Ngenxa yokwanda kwe-viscosity yesisombululo se-pore, i-cellulose ether inciphisa ukuhamba kwama-ion esixazululweni, ngaleyo ndlela ibambezele inqubo ye-hydration.
Isikhathi sokuthumela: Feb-04-2023