Focus on Cellulose ethers

I-cellulose ether isebenzisa udaka olomile oluxubile

I-cellulose ether isebenzisa udaka olomile oluxubile

Imiphumela ye-cellulose ethers eyodwa evamile kanye nama-ether axubile odaka oluxutshwe okomile ekugcineni kwamanzi nokuqina, uketshezi, ukusebenza, umphumela wokungenisa umoya, namandla odaka oluxutshwe okomile kuyabuyekezwa.Kungcono kune-ether eyodwa;isiqondiso sokuthuthukiswa kokusetshenziswa kwe-cellulose ether odakeni oluxutshwe owomile kulindeleke.

Amagama angukhiye:i-cellulose ether;udaka oluxutshwe owomile;I-ether eyodwa;i-ether ehlanganisiwe

 

Udaka lwendabuko lunezinkinga ezinjengokuqhekeka kalula, ukopha, ukusebenza kabi, ukungcoliswa kwemvelo, njll., futhi kancane kancane luzothathelwa indawo udaka oluxutshwe owomile.Udaka oluxutshwe okomile, olwaziwa nangokuthi udaka oluxutshwe ngaphambili (olulomile), imfucumfucu eyomile, ingxube eyomile, udaka lwempushana eyomile, udaka oluxutshwe okomile, luwudaka oluxutshwe kancane oluphelile ngaphandle kokuhlanganisa amanzi.I-Cellulose ether inezinto ezinhle kakhulu ezifana nokujiya, i-emulsification, ukumiswa, ukwakheka kwefilimu, i-colloid evikelayo, ukugcinwa komswakama, nokunamathela, futhi iyinhlanganisela ebalulekile odakeni oluxubekile.

Leli phepha lethula izinzuzo, ezimbi kanye nokuthuthuka kwethrendi ye-cellulose ether ekusetshenzisweni kodaka oluxutshwe okomile.

 

1. Izici zodaka oluxutshwe okomile

Ngokwezidingo zokwakha, udaka oluxutshwe okomile lungasetshenziswa ngemva kokukalwa ngokunembile futhi luxutshwe ngokugcwele endaweni yokusebenzela yokukhiqiza, bese luxutshwa namanzi endaweni yokwakha ngokuvumelana nesilinganiso esinqunyiwe sikasimende samanzi.Uma kuqhathaniswa nodaka lwendabuko, udaka oluxutshwe okomile lunezinzuzo ezilandelayo:Izinga elihle kakhulu, udaka oluxutshwe okomile lukhiqizwa ngokuya ngefomula yesayensi, i-automation enkulu, ehambisana nezixube ezifanele ukuze kuqinisekiswe ukuthi umkhiqizo ungahlangabezana nezidingo ezikhethekile zekhwalithi;Okunhlobonhlobo Okuchichimayo, ama-mortars okusebenza ahlukahlukene angakhiqizwa ngokuya ngezidingo ezahlukahlukene;Ukusebenza okuhle kokwakhiwa, ukusebenziseka kalula nokukhuhla, ukususa isidingo sokumanzisa ngaphambi kokumanzisa kanye nokugcinwa kokunisela okulandelayo;Kulula ukuyisebenzisa, vele ungeze amanzi futhi ugovuze, kulula ukuthutha nokugcina, elungele ukuphathwa kokwakhiwa;ukuvikelwa okuluhlaza kanye nemvelo, akukho uthuli endaweni yokwakha, akukho zinqwaba ezihlukahlukene zezinto zokusetshenziswa, ukunciphisa umthelela endaweni ezungezile;ukonga, udaka oluxutshwe okomile lugwema ukusetshenziswa okungenangqondo kwezinto ezingavuthiwe ngenxa yezithako ezinengqondo, futhi lilungele ukwenziwa ngemishini Ukwakhiwa kufinyeza umjikelezo wokwakha futhi kunciphisa izindleko zokwakha.

I-Cellulose ether iyinhlanganisela ebalulekile yodaka oluxutshwe okomile.I-Cellulose ether ingakha inhlanganisela ye-calcium-silicate-hydroxide (CSH) ezinzile nesihlabathi nosimende ukuze ihlangabezane nezidingo zezinto ezintsha zodaka ezisebenza kahle.

 

2. I-cellulose ether njengengxube

I-Cellulose ether iyi-polymer yemvelo eguquliwe lapho ama-athomu e-hydrogen eqenjini le-hydroxyl kuyunithi yesakhiwo se-cellulose athathelwa indawo amanye amaqembu.Uhlobo, inani kanye nokusatshalaliswa kwamaqembu abambe iqhaza kuketango eliyinhloko le-cellulose kunquma uhlobo nemvelo.

Iqembu le-hydroxyl ku-cellulose ether molecular chain likhiqiza i-intermolecular oxygen bond, engathuthukisa ukufana nokuphelela kwe-cement hydration;ukwandisa ukungaguquguquki kodaka, shintsha i-rheology kanye nokucindezelwa kodaka;thuthukisa ukumelana nokuqhekeka kodaka;Ukufaka umoya, ukuthuthukisa ukusebenza kodaka.

2.1 Ukusetshenziswa kwe-carboxymethyl cellulose

I-Carboxymethylcellulose (CMC) iyi-ayoni eyodwa ye-cellulose ether encibilika emanzini, futhi usawoti wayo we-sodium uvame ukusetshenziswa.I-CMC ehlanzekile iyimpushana emhlophe noma eyi-milky emhlophe noma ama-granules, ayinaphunga futhi ayinambitheki.Izinkomba eziyinhloko zokukala ikhwalithi ye-CMC yi-degree of substitution (DS) kanye ne-viscosity, ukucaca kanye nokuzinza kwesixazululo.

Ngemva kokwengeza i-CMC odakeni, iba nemiphumela esobala yokujiya kanye nokugcinwa kwamanzi, futhi umphumela wokujiya uncike kakhulu esisindweni sayo samangqamuzana nezinga lokushintsha.Ngemva kokungeza i-CMC amahora angu-48, kukalwa ukuthi izinga lokumuncwa kwamanzi lesampula lodaka lehlile.Uma liphansi izinga lokumunca amanzi, izinga lokugcinwa kwamanzi liphezulu;umphumela wokugcina amanzi ukhuphuka ngokwanda kokwengezwa kwe-CMC.Ngenxa yomphumela omuhle wokugcina amanzi, ingaqinisekisa ukuthi ingxube yodaka oluxubile alophi noma aluhlukanisi.Njengamanje, i-CMC isetshenziswa kakhulu njenge-ejenti yokulwa nokukhukhula emadamini, ezikhumulweni zemikhumbi, emabhulohweni nakwezinye izakhiwo, okunganciphisa umthelela wamanzi kusimende namaqoqo amahle futhi kunciphise ukungcoliswa kwemvelo.

I-CMC iyinhlanganisela ye-ionic futhi inezidingo eziphezulu kusimende, ngaphandle kwalokho ingasabela nge-Ca(OH)2 encibilikiswe kusimende ngemva kokuxutshwa nodaka lukasimende ukuze yakhe i-calcium carboxymethylcellulose engancibiliki emanzini futhi ilahlekelwe yi-viscosity yayo, kunciphisa kakhulu ukusebenza kokugcinwa kwamanzi. ye-CMC ikhubazekile;ukumelana ne-enzyme ye-CMC kubi.

2.2 Ukusetshenziswa kwei-hydroxyethyl cellulosekanye ne-hydroxypropyl cellulose

I-Hydroxyethyl cellulose (HEC) kanye ne-hydroxypropyl cellulose (HPC) ama-ether angama-cellulose angeyona ionic ancibilika emanzini anokumelana nosawoti ophezulu.I-HEC izinzile ekushiseni;ancibilika kalula emanzini abandayo nashisayo;lapho inani le-pH liyi-2-12, i-viscosity ishintsha kancane.I-HPC iyancibilika emanzini angaphansi kwama-40°C kanye nenani elikhulu lama-solvents e-polar.Inomsebenzi we-thermoplasticity nomsebenzi wangaphezulu.Uma izinga lokushintsha liphakeme, izinga lokushisa lamanzi lapho i-HPC ingancibilika liyancipha.

Njengoba inani le-HEC elingezwe ku-mortar likhula, amandla okucindezela, amandla okuqina nokumelana nokugqwala kwe-mortar kwehla ngesikhathi esifushane, futhi ukusebenza kushintsha kancane ngokuhamba kwesikhathi.I-HEC iphinde ithinte ukusatshalaliswa kwama-pores odakeni.Ngemva kokwengeza i-HPC odakeni, i-porosity yodaka iphansi kakhulu, futhi amanzi adingekayo ayancipha, ngaleyo ndlela anciphise ukusebenza kokusebenza kodaka.Ekusetshenzisweni kwangempela, i-HPC kufanele isetshenziswe kanye ne-plasticizer ukuze kuthuthukiswe ukusebenza kodaka.

2.3 Ukusetshenziswa kwe-methyl cellulose

I-Methylcellulose (MC) i-non-ionic single cellulose ether, engahlakaza ngokushesha futhi ivuvuke emanzini ashisayo ku-80-90.°C, futhi zincibilike ngokushesha ngemva kokupholisa phansi.Isixazululo esinamanzi se-MC singakha ijeli.Lapho ishisa, i-MC ayincibiliki emanzini ukuze yakhe ijeli, futhi lapho ipholile, ijeli iyancibilika.Lesi simo singahlehliswa ngokuphelele.Ngemva kokwengeza i-MC odakeni, umphumela wokugcina amanzi ngokusobala uthuthukisiwe.Ukugcinwa kwamanzi kwe-MC kuncike ku-viscosity yayo, izinga lokushintsha, inhlawulo, kanye nenani elingeziwe.Ukwengeza i-MC kungathuthukisa indawo yokulwa nodaka;thuthukisa ukuthambisa nokufana kwezinhlayiya ezihlakazekile, wenze udaka lube bushelelezi futhi lufane, umphumela wokudonsa nokushelela ungcono kakhulu, futhi ukusebenza komsebenzi kuyathuthukiswa.

Inani le-MC elingeziwe linethonya elikhulu kudaka.Uma okuqukethwe kwe-MC kungaphezulu kuka-2%, amandla odaka ancishiswa abe uhhafu woqobo.Umphumela wokugcinwa kwamanzi ukhula ngokunyuka kwe-viscosity ye-MC, kodwa lapho i-viscosity ye-MC ifinyelela inani elithile, ukuncibilika kwe-MC kuncipha, ukugcinwa kwamanzi akushintshi kakhulu, futhi ukusebenza kokwakha kuncipha.

2.4 Ukusetshenziswa kwe-hydroxyethylmethylcellulose kanye ne-hydroxypropylmethylcellulose

I-ether eyodwa inobubi bokuhlakazeka okubi, i-agglomeration kanye nokuqina ngokushesha lapho inani elingeziwe lilincane, kanye nama-voids amaningi odakeni lapho inani elingeziwe lilikhulu, futhi ukuqina kukakhonkolo kuncipha;ngakho-ke, ukusebenza, amandla okucindezela, namandla okuguquguquka Ukusebenza akufanelekile.Ama-ether ahlanganisiwe anganqoba ukushiyeka kwama-ether awodwa ngezinga elithile;inani elingeziwe lincane kunele-ether eyodwa.

I-Hydroxyethylmethylcellulose (HEMC) kanye ne-hydroxypropylmethylcellulose (HPMC) ama-ether e-cellulose ayingxube ye-nonionic enezakhiwo ze-ether eyodwa ebambele ye-cellulose.

Ukubonakala kwe-HEMC kumhlophe, i-powder emhlophe noma i-granule, ayinaphunga futhi ayinambitheki, i-hygroscopic, ayincibiliki emanzini ashisayo.Ukuqedwa akuthintwa inani le-pH (elifana ne-MC), kodwa ngenxa yokwengezwa kwamaqembu e-hydroxyethyl ochungechungeni lwamangqamuzana, i-HEMC inokubekezelela usawoti okuphakeme kune-MC, kulula ukuchithwa emanzini, futhi inokushisa okuphezulu kwe-condensation.I-HEMC inokugcinwa kwamanzi okunamandla kune-MC;ukuzinza kwe-viscosity, ukumelana nesikhutha, kanye nokuhlakazeka kunamandla kune-HEC.

I-HPMC iyimpushana emhlophe noma emhlophe, ayinabo ubuthi, ayinambitheki futhi ayinaphunga.Ukusebenza kwe-HPMC enemininingwane ehlukene kuhluke kakhulu.I-HPMC incibilika emanzini abandayo ibe isixazululo se-colloidal esicacile noma esithuthuke kancane, esincibilika kwezinye izinyibilikisi zemvelo, futhi futhi inyibilika emanzini.Izinyibilikisi ezixubile zezincibilikizi eziphilayo, njenge-ethanol ngesilinganiso esifanele, emanzini.Isixazululo se-aqueous sinezici zomsebenzi ophezulu wendawo, ukukhanya okuphezulu nokusebenza okuzinzile.Ukuhlakazwa kwe-HPMC emanzini nakho akuthintwa i-pH.I-Solubility iyahlukahluka nge-viscosity, i-viscosity ephansi, i-solubility enkulu.Ngokuncipha kokuqukethwe kwe-methoxyl kuma-molecule e-HPMC, iphoyinti lejeli le-HPMC liyakhula, ukuncibilika kwamanzi kuncipha, nomsebenzi ongaphezulu nawo uyehla.Ngaphezu kwezici ezivamile zamanye ama-cellulose ethers, i-HPMC futhi inokumelana okuhle kukasawoti, ukuzinza kwe-dimensional, ukumelana nama-enzyme, kanye nokuhlakazeka okuphezulu.

Imisebenzi esemqoka ye-HEMC kanye ne-HPMC odakeni oluxutshwe okomile imi kanje.Ukugcinwa kwamanzi okuhle.I-HEMC kanye ne-HPMC ingaqinisekisa ukuthi udaka ngeke lubangele izinkinga ezifana nesihlabathi, i-powdering kanye nokunciphisa amandla omkhiqizo ngenxa yokuntuleka kwamanzi nokungaphelele kwe-cement hydration.Thuthukisa ukufana, ukusebenza kanye nokuqina komkhiqizo.Lapho inani le-HPMC elingeziwe likhulu kuno-0.08%, ukucindezelwa kwesivuno kanye ne-viscosity yepulasitiki yodaka nakho kuyanda ngokwanda kwenani le-HPMC.Njenge-ejenti yokungenisa umoya.Uma okuqukethwe kwe-HEMC ne-HPMC kungu-0.5%, okuqukethwe kwegesi kukhulu, cishe ku-55%.Amandla aguquguqukayo namandla okucindezela odaka.Thuthukisa ukusebenza.Ukwengezwa kwe-HEMC kanye ne-HPMC kusiza ukufakwa kwamakhadi kodaka longqimba oluncane kanye nokugandaywa kodaka olukhonkolo.

I-HEMC ne-HPMC zingabambezela ukugeleza kwezinhlayiya zodaka, i-DS iyisici esibaluleke kakhulu esithinta ukugeleza kwamanzi, futhi umphumela wokuqukethwe kwe-methoxyl ekubambezelekeni kwe-hydration mkhulu kunokuqukethwe kwe-hydroxyethyl ne-hydroxypropyl.

Kumele kuqashelwe ukuthi i-cellulose ether inethonya eliphindwe kabili ekusebenzeni kodaka, futhi ingadlala indima enhle uma isetshenziswe kahle, kodwa izoba nomphumela omubi uma isetshenziswe ngendlela engafanele.Ukusebenza kodaka oluxutshwe okomile okokuqala kuhlobene nokuvumelana nezimo kwe-cellulose ether, futhi i-cellulose ether esebenzayo nayo ihlobene nezici ezifana nenani nokuhleleka kokwengezwa.Ezinhlelweni ezingokoqobo, uhlobo olulodwa lwe-cellulose ether lungakhethwa, noma izinhlobo ezahlukene ze-cellulose ether zingasetshenziswa ngokuhlangana.

 

3. I-Outlook

Ukuthuthukiswa okusheshayo kodaka oluxutshwe okomile kunikeza amathuba nezinselelo zokuthuthukiswa nokusetshenziswa kwe-cellulose ether.Abacwaningi nabakhiqizi kufanele babambe ithuba lokuthuthukisa izinga labo lobuchwepheshe, futhi basebenze kanzima ukuze bandise izinhlobo futhi bathuthukise ukuzinza komkhiqizo.Ngenkathi ihlangabezana nezidingo zokusetshenziswa kodaka oluxutshwe okomile, izuze ukugxuma embonini ye-cellulose ether.


Isikhathi sokuthumela: Feb-06-2023
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