Ikhwalithi ye-cellulose hpmc inquma ikhwalithi yodaka

Ngodaka oluxutshwe okomile, inani elingeziwe le-hydroxypropyl methylcellulose HPMC liphansi kakhulu, kodwa lingathuthukisa kakhulu ukusebenza kodaka olumanzi, futhi liyisithasiselo esiyinhloko esithinta ukusebenza kokwakhiwa kodaka. I-cellulose ethers enamazinga ahlukene e-viscosity kanye nezengezo zinomthelela omuhle ekusebenzeni kwe-powder mortar eyomile. 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. Izici ezithinta umphumela wokugcina amanzi we-powder mortar eyomile zihlanganisa inani le-HPMC elingeziwe, i-viscosity ye-HPMC, 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 kakhulu 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-HPMC esivame ukuyisebenzisa iyi-ether exubile. I-Hydroxypropyl methylcellulose ether I-HPMC iwumkhiqizo 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

I-HPMC isetshenziswa kakhulu ezintweni zokwakha, i-latex coatings, imithi, amakhemikhali ansuku zonke, njll. Isetshenziswa njenge-thickener, i-ejenti yokugcina amanzi, i-stabilizer, i-disperant kanye ne-ejenti yokwakha ifilimu.

2. Ukugcinwa kwamanzi kwe-cellulose ether: Ekukhiqizeni izinto zokwakha, ikakhulukazi udaka lwempuphu eyomile, i-cellulose ether idlala indima engenakushintshwa, ikakhulukazi ekukhiqizeni udaka olukhethekile (udaka oluguquliwe), lubalulekile futhi luyingxenye 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, iyavuvukala 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-viscosity ye-cellulose ether, inani elingeziwe, ukucoleka kwezinhlayiya kanye nezinga lokushisa lokusetshenziswa. Uma kukhulu i-viscosity ye-cellulose ether, kuba ngcono ukusebenza kokugcinwa kwamanzi. Ngokuvamile, ukuphakama kwe-viscosity, kuba ngcono umphumela wokugcina amanzi. 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. 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-HPMC esetshenziselwa udaka lwempushana eyomile idingeka ukuthi ibe yimpushana, enokuqukethwe kwamanzi aphansi, futhi 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-HPMC yengezwa ngamanzi ukuze ihlakaze ama-agglomerate, kunzima kakhulu ukuhlakazeka nokuhlakazeka. Ngodaka olufuthwe ngokwakhiwa kwemishini, imfuneko yokucwenga iphakeme ngenxa yesikhathi esifushane sokuxuba. Ukucoleka kwe-HPMC nakho kunomthelela othize ekugcineni 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-HPMC 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.

3. Ukuqina kanye ne-thixotropy ye-cellulose ether: Umsebenzi wesibili we-cellulose ether-umphumela wokuqina uncike: izinga le-polymerization ye-cellulose ether, ukugxila kwesisombululo, 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 isisombululo se-HPMC esine-viscosity ephansi, isisombululo sokuhlushwa esingu-10% -15% singalungiswa, i-medium-viscosity HPMC ingalungiswa isixazululo esingu-5% -10%, kanye ne-high-viscosity HPMC ingalungisa kuphela isisombululo esingu-2% -3%, kanye ne-viscosity. ye-cellulose ether imvamisa Ukugreda kuphinde kubekwe ngezigaba ngesixazululo esingu-1% -2%. Isisindo esiphezulu se-cellulose ether sinokujiya okuphezulu. Ama-polymers anesisindo samangqamuzana ahlukene anama-viscosity ahlukene kusixazululo esifanayo sokuhlushwa. Izinga eliphezulu le-polymerization. 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. 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 se-aqueous cellulose cellulose ether esine-high-viscosity sine-thixotropy ephezulu, ephinde ibe yisici esikhulu se-cellulose ether. Ngakho-ke, ama-cellulose ethers ebanga elifanayo le-viscosity ahlala ebonisa izici ezifanayo ze-rheological inqobo nje uma ukugxila kanye nezinga lokushisa 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: Umsebenzi wesithathu we-cellulose ether ukulibazisa inqubo yokufakwa kwe-hydration kasimende. 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. Uma uphezulu ukugcwala kwe-cellulose ether kujeli yamaminerali, kulapho ubonakala khona umphumela wokubambezeleka kokufakwa kwamanzi. I-Cellulose ether ayilibazisi nje kuphela ukusetha, kodwa futhi ibambezela inqubo yokuqina yesistimu yodaka lukasimende. Umphumela wokuvinjelwa kwe-cellulose ether awuncikile kuphela ekugxilweni kwayo ohlelweni lwejeli yamaminerali, kodwa futhi nesakhiwo samakhemikhali. Uma ungcono umphumela wokuvinjelwa kwe-cellulose ether, unamandla umphumela wokuvinjelwa kokushintshwa kwe-hydrophilic kunokushintshwa okwandisa amanzi. Kodwa-ke, i-viscosity ye-cellulose ether ayinamthelela omncane ku-simende hydration kinetics. Ngokukhula kokuqukethwe kwe-cellulose ether, isikhathi sokusetha sodaka sikhula kakhulu. Kukhona ukuhlobana okuhle okungaqondile phakathi kwesikhathi sokuqala sokusetha sodaka nokuqukethwe kwe-cellulose ether, kanye nokuhlobana okuhle komugqa phakathi kwesikhathi sokugcina sokusetha nokuqukethwe kwe-cellulose ether. Singakwazi ukulawula isikhathi sokusebenza kodaka ngokushintsha inani le-cellulose ether. Ukufingqa, odakeni oluxubekile, i-cellulose ether idlala indima ekugcineni amanzi, ukuqina, ukubambezeleka kwamandla kasimende, kanye nokwenza ngcono ukusebenza komsebenzi wokwakha. Umthamo omuhle wokugcina amanzi wenza ukugeleza kukasimende kuphelele, kungathuthukisa i-viscosity emanzi yodaka olumanzi, kukhuphule amandla okubopha odaka, futhi kulungise isikhathi. Ukwengeza i-cellulose ether kudaka lokufafaza lomshini kungathuthukisa ukusebenza kokufuthwa noma ukumpompa namandla esakhiwo sodaka. Ngakho-ke, i-cellulose ether isetshenziswa kabanzi njengesengezo esibalulekile odakeni oluxubile.