Focus on Cellulose ethers

I-ether ye-cellulose isebenzisa kudaka olomileyo oluxutyiweyo

I-ether ye-cellulose isebenzisa kudaka olomileyo oluxutyiweyo

Imiphumo yee-ethers ezininzi eziqhelekileyo ze-cellulose kunye ne-ethers ezixutywe kwi-ether edibeneyo eyomileyo ekugcinweni kwamanzi kunye nokuqina, i-fluidity, ukusebenza, i-air-entraining effect, kunye namandla omdaka odibeneyo owomileyo ayahlaziywa.Kulunge ngakumbi kuneetha enye;isalathiso sophuhliso lokusetyenziswa kwe-cellulose ether kudaka oluxutywe owomileyo lulindelwe.

Amagama angundoqo:i-cellulose ether;udaka oluxutyiweyo olomileyo;iether enye;i-ether edibeneyo

 

Udaka lwemveli luneengxaki ezifana nokuqhekeka lula, ukopha, ukusebenza kakubi, ukungcoliseka kwendalo, njl. njl., kwaye ngokuthe ngcembe luya kutshintshwa ngodaka oluxubeneyo olomileyo.Udaka oluxubeneyo elomileyo, nokwaziwa ngokuba ludaka oluxutywe ngaphambili (olulomileyo), umgubo owomileyo, umxube owomileyo, udaka olomileyo, udaka oluxubeneyo olomileyo, ludaka oluxubeneyo olungagqibekanga ngaphandle kokuxuba amanzi.I-ether ye-cellulose ineempawu ezibalaseleyo ezifana nokuqina, i-emulsification, ukumiswa, ukubunjwa kwefilimu, i-colloid ekhuselayo, ukugcinwa komswakama, kunye nokunamathela, kwaye iyingxube ebalulekileyo kwi-dry-mixed mortar.

Eli phepha lizisa izinto eziluncedo, ezingeloncedo kunye nophuhliso lwe-cellulose ether ekusetyenzisweni kodaka oluxutyiweyo.

 

1. Iimpawu zodaka oluxutyiweyo olomileyo

Ngokweemfuno zokwakha, udaka oluxutyiweyo lunokusetyenziswa emva kokuba lulinganiswe ngokuchanekileyo kwaye luxutywe ngokupheleleyo kwindawo yokusebenzela yokuvelisa, emva koko luxutywe namanzi kwindawo yokwakha ngokomlinganiselo omiselweyo wamanzi-samente.Xa kuthelekiswa nodaka lwemveli, udaka oluxutyiweyo olomileyo lunezi nzuzo zilandelayo:Umgangatho ogqwesileyo, udaka oluxubeneyo olomileyo luveliswa ngokwefomula yesayensi, i-automation enkulu, idityaniswa ne-admixtures efanelekileyo ukuqinisekisa ukuba imveliso inokuhlangabezana neemfuno ezikhethekileyo zomgangatho;Iintlobo-ntlobo Zininzi, iintsimbi zokusebenza ezahlukeneyo zinokuveliswa ngokweemfuno ezahlukeneyo;Ukusebenza kakuhle kolwakhiwo, kulula ukuyisebenzisa kunye nokukhuhla, ukuphelisa imfuno ye-substrate yangaphambili yokumanzisa kunye nokugcinwa kokunkcenkceshela okulandelayo;Kulula ukuyisebenzisa, yongeza nje amanzi kunye nokushukumisa, kulula ukuthutha kunye nokugcina, ilungele ulawulo lokwakha;ukukhuselwa okuluhlaza kunye nokusingqongileyo, akukho luthuli kwindawo yokwakha, akukho zimfumba ezahlukeneyo zezinto ezibonakalayo, ukunciphisa impembelelo kwindawo engqongileyo;udaka olunoqoqosho, oluxubeneyo olomileyo luphepha ukusetyenziswa ngokungekho ngqiqweni kwemathiriyeli ekrwada ngenxa yezithako ezinengqiqo, kwaye lufanelekile kumatshini Ulwakhiwo lunciphisa umjikelo wokwakha kwaye lunciphise iindleko zokwakha.

I-ether ye-Cellulose ngumxube obalulekileyo wodaka oluxutyiweyo olomileyo.I-ether ye-cellulose inokwenza i-calcium-silicate-hydroxide (CSH) ezinzileyo kunye nesanti kunye nesamente ukuhlangabezana neemfuno eziphezulu zokusebenza kwezinto ezintsha zodaka.

 

2. I-ether ye-cellulose njengomxube

I-cellulose ether yipolymer yendalo elungisiweyo apho ii-athomu ze-hydrogen kwiqela le-hydroxyl kwiyunithi yesakhiwo se-cellulose ithathelwa indawo ngamanye amaqela.Uhlobo, ubungakanani kunye nokuhanjiswa kwamaqela abambeleyo kwikhonkco eliphambili leselulosi limisela uhlobo kunye nendalo.

Iqela le-hydroxyl kwi-cellulose ether molecular chain livelisa i-intermolecular oxygen bonds, enokuphucula ukufana kunye nokuphelela kwe-cement hydration;ukwandisa ukuhambelana kodaka, ukutshintsha i-rheology kunye nokunyanzeliswa kodaka;ukuphucula ukumelana nokuqhekeka kodaka;Ukungenisa umoya, ukuphucula ukusebenza kodaka.

2.1 Ukusetyenziswa kwe-carboxymethyl cellulose

ICarboxymethylcellulose (CMC) yi-ionic yamanzi enyibilikayo ye-cellulose ether enye, kwaye ityuwa yayo yesodium idla ngokusetyenziswa.I-CMC ecocekileyo imhlophe okanye i-milky white fibrous powder okanye iigranules, ayinavumba kwaye ayinancasa.Iimpawu eziphambili zokulinganisa umgangatho we-CMC yi-degree of substitution (DS) kunye ne-viscosity, ukungafihli kunye nokuzinza kwesisombululo.

Emva kokongeza i-CMC kudaka, inokuqina okucacileyo kunye neziphumo zokugcina amanzi, kwaye isiphumo sokuqina sixhomekeke ubukhulu becala kubunzima bemolekyuli kunye nenqanaba lokutshintsha.Emva kokongeza i-CMC kwiiyure ezingama-48, kwalinganiswa ukuba izinga lokufunxa amanzi kwisampulu yodaka lehlile.Okukhona usezantsi umyinge wokufunxa kwamanzi, kokukhona uphezulu ukugcinwa kwamanzi;isiphumo sogcino lwamanzi siyenyuka ngokwanda kokongezwa kwe-CMC.Ngenxa yesiphumo esihle sokugcinwa kwamanzi, kunokuqinisekisa ukuba umxube wodaka oxutywe owomileyo awunalo igazi okanye uyahlula.Okwangoku, i-CMC isetyenziswa kakhulu njenge-anti-scouring agent kumadama, iidokhi, iibhulorho kunye nezinye izakhiwo, ezinokunciphisa impembelelo yamanzi kwisamente kunye ne-aggregates emihle kunye nokunciphisa ukungcoliseka kwendalo.

I-CMC iyikhompawundi ye-ionic kwaye ineemfuno eziphezulu kwi-samente, ngaphandle koko inokusabela nge-Ca (OH) 2 echithwe kwi-samente emva kokuxutywa kwi-sement slurry ukwenza i-calcium carboxymethylcellulose engenamanzi kwaye ilahlekelwe yi-viscosity yayo, ukunciphisa kakhulu ukusebenza kokugcinwa kwamanzi. yeCMC yonakele;ukuxhathisa i-enzyme ye-CMC imbi.

2.2 Ukusetyenziswa kwei-hydroxyethyl cellulosekunye ne-hydroxypropyl cellulose

I-Hydroxyethyl cellulose (HEC) kunye ne-hydroxypropyl cellulose (i-HPC) zi-non-ionic yamanzi-ethers ze-cellulose ezixutywe ngamanzi kunye nokuxhathisa ityuwa ephezulu.I-HEC izinzile ukutshisa;Inyibilika ngokulula emanzini abandayo nashushu;xa ixabiso le-pH li-2-12, i-viscosity iyatshintsha kancinci.I-HPC iyanyibilika emanzini angaphantsi kwama-40°C kunye nenani elikhulu le-solvents polar.Ine-thermoplasticity kunye nomsebenzi ongaphezulu.Iqondo eliphezulu lokutshintshwa, lisezantsi ubushushu bamanzi apho i-HPC inokunyibilika khona.

Njengoko inani le-HEC elongeziweyo kwi-mortar linyuka, amandla oxinzelelo, amandla okunyamezela kunye nokuxhatshazwa kwe-corrosion ye-corrosion yehla ngexesha elifutshane, kwaye ukusebenza kutshintsha kancinci ngexesha.I-HEC iphinda ichaphazele ukuhanjiswa kweepores kumdaka.Emva kokongeza i-HPC kumdaka, i-porosity yodaka iphantsi kakhulu, kwaye amanzi afunekayo ayancitshiswa, ngaloo ndlela ukunciphisa ukusebenza kodaka.Ekusetyenzisweni okwenyani, i-HPC kufuneka isetyenziswe kunye ne-plasticizer ukuphucula ukusebenza kodaka.

2.3 Ukusetyenziswa kwe-methyl cellulose

I-Methylcellulose (MC) yi-ether ye-cellulose e-non-ionic enye, enokuthi isasazeke ngokukhawuleza kwaye idumbe emanzini ashushu kwi-80-90.°C, kwaye unyibilike ngokukhawuleza emva kokupholisa phantsi.Isisombululo samanzi se-MC sinokwenza ijeli.Xa ishushu, i-MC ayinyibiliki emanzini ukwenza i-gel, kwaye xa ipholile, i-gel iyanyibilika.Lo mcimbi uguqulwa ngokupheleleyo.Emva kokongeza i-MC kumdaka, umphumo wokugcinwa kwamanzi ngokucacileyo uphuculwe.Ukugcinwa kwamanzi e-MC kuxhomekeke kwi-viscosity yayo, iqondo lokutshintshela, ukucoleka, kunye nesixa esongezelelweyo.Ukongeza i-MC kunokuphucula ipropati yokuchasana nodaka;ukuphucula i-lubricity kunye nokufana kwamasuntswana ahlakazekileyo, yenza udaka lube lula kwaye lufane ngakumbi, umphumo we-troweling kunye ne-smooth ilungile, kwaye ukusebenza komsebenzi kuphuculwe.

Isixa se-MC esongeziweyo sinempembelelo enkulu kumdaka.Xa umxholo we-MC ungaphezu kwe-2%, amandla omdaka ancitshiswa ukuya kwisiqingatha sokuqala.Isiphumo sokugcinwa kwamanzi sinyuka ngokunyuka kwe-viscosity ye-MC, kodwa xa i-viscosity ye-MC ifikelela kwixabiso elithile, i-solubility ye-MC iyancipha, ukugcinwa kwamanzi akutshintshi kakhulu, kwaye umsebenzi wokwakha uyancipha.

2.4 Ukusetyenziswa kwe-hydroxyethylmethylcellulose kunye ne-hydroxypropylmethylcellulose

I-ether enye ine-disadvantages ye-dispersibility embi, i-agglomeration kunye nokuqina ngokukhawuleza xa imali eyongeziweyo incinci, kunye ne-voids eninzi kwi-mortar xa imali eyongeziweyo inkulu, kwaye ubulukhuni bekhonkrithi buyawohloka;ngoko ke, ukusebenza, amandla oxinzelelo, kunye namandla okuguquguquka Ukusebenza akufanelekile.Ii-ether ezixutyiweyo zinokuzoyisa iintsilelo zee-ether enye ukusa kumlinganiselo othile;imali eyongeziweyo ingaphantsi kwe-ether enye.

I-Hydroxyethylmethylcellulose (HEMC) kunye ne-hydroxypropylmethylcellulose (HPMC) zii-ethers ze-cellulose ezixubeneyo ze-nonionic ezineempawu ze-ether nganye ebambeleyo ye-cellulose.

Ukubonakala kwe-HEMC kumhlophe, i-powder emhlophe okanye i-granule, i-odorless kunye ne-tasteless, i-hygroscopic, i-insoluble emanzini ashushu.Ukuchithwa akuchaphazeli ixabiso le-pH (elifana ne-MC), kodwa ngenxa yokongezwa kwamaqela e-hydroxyethyl kwi-chain chain, i-HEMC inokunyamezela ityuwa ngaphezu kwe-MC, kulula ukuyichitha emanzini, kwaye inokushisa okuphezulu kwe-condensation.I-HEMC inokugcinwa kwamanzi okunamandla kune-MC;Ukuzinza kwe-viscosity, ukuxhathisa ukubola, kunye ne-dispersibility yomelele kune-HEC.

I-HPMC ingumgubo omhlophe okanye ongekho-mhlophe, awunatyhefu, awunancasa kwaye awunavumba.Ukusebenza kwe-HPMC eneenkcukacha ezahlukeneyo kwahluke kakhulu.I-HPMC inyibilika emanzini abandayo ibe yicolloidal ecacileyo okanye engqukuva kancinane, enyibilikayo kwezinye izinyibilikisi eziphilayo, kwaye zinyibilika emanzini.Izinyibilikisi ezixutyiweyo zezinyibilikisi eziphilayo, ezifana ne-ethanol ngomlinganiselo ofanelekileyo, emanzini.Isisombululo samanzi sineempawu zomsebenzi ophezulu ophezulu, ukukhanya okuphezulu kunye nokusebenza okuzinzile.Ukuchithwa kwe-HPMC emanzini nako akuchatshazelwa yi-pH.I-Solubility iyahluka kunye ne-viscosity, i-viscosity ephantsi, i-solubility enkulu.Ngokuncipha komxholo we-methoxyl kwiimolekyuli ze-HPMC, i-gel point ye-HPMC iyanda, ukunyibilika kwamanzi kuncipha, kunye nomsebenzi womphezulu nawo uyancipha.Ukongeza kwiimpawu eziqhelekileyo zezinye ii-cellulose ethers, i-HPMC ikwanako ukumelana netyuwa elungileyo, ukuzinza kwe-dimensional, ukumelana ne-enzyme, kunye nokusasazeka okuphezulu.

Imisebenzi ephambili ye-HEMC kunye ne-HPMC kwi-dry-mixed mortar yile ilandelayo.Ukugcinwa kakuhle kwamanzi.I-HEMC kunye ne-HPMC inokuqinisekisa ukuba udaka aluyi kubangela iingxaki ezifana ne-sanding, i-powdering kunye nokunciphisa amandla emveliso ngenxa yokungabikho kwamanzi kunye ne-cement hydration engaphelelanga.Ukuphucula ukufana, ukusebenza kunye nokuqina kwemveliso.Xa isixa HPMC yongezwa mkhulu kune 0.08%, uxinzelelo isivuno kunye viscosity zeplastiki yodaka kwakhona ukwanda kunye nokwanda isixa HPMC.Njenge-arhente yokungenisa umoya.Xa umxholo we-HEMC kunye ne-HPMC ngu-0.5%, umxholo wegesi ngowona mkhulu, malunga ne-55%.Amandla e-flexural kunye namandla acinezelayo odaka.Ukuphucula ukusebenza.Ukongezwa kwe-HEMC kunye ne-HPMC kuququzelela ukufakwa kwamakhadi odaka olucekethekileyo kunye nokupeyintwa kodaka lokutyabeka.

I-HEMC kunye ne-HPMC inokulibazisa i-hydration ye-particle particles, i-DS iyona nto ibaluleke kakhulu echaphazela i-hydration, kwaye umphumo womxholo we-methoxyl kwi-hydration yokulibaziseka inkulu kunomxholo we-hydroxyethyl kunye ne-hydroxypropyl.

Kufuneka kuqatshelwe ukuba i-cellulose ether inefuthe eliphindwe kabini ekusebenzeni kodaka, kwaye inokudlala indima enhle xa isetyenziswe ngokufanelekileyo, kodwa iya kuba nefuthe elibi xa lisetyenziswe ngokungafanelekanga.Ukusebenza kodaka oluxubeneyo owomileyo okokuqala kuhambelana nokuguquguquka kwe-ether ye-cellulose, kwaye i-ether ye-cellulose esebenzayo nayo ihambelana nezinto ezifana nemali kunye nomyalelo wokongezwa.Kwiinkqubo ezisebenzayo, uhlobo olulodwa lwe-ether ye-cellulose lunokukhethwa, okanye iintlobo ezahlukeneyo ze-cellulose ether zingasetyenziswa ngokudibeneyo.

 

3. Umbono

Uphuhliso olukhawulezayo lodaka oluxutyiweyo lunika amathuba kunye nemingeni yophuhliso kunye nokusetyenziswa kwe-cellulose ether.Abaphandi kunye nabavelisi kufuneka babambe ithuba lokuphucula inqanaba labo lobugcisa, kwaye basebenze nzima ukunyusa iintlobo kunye nokuphucula ukuzinza kwemveliso.Ngelixa uhlangabezana neemfuno zokusetyenziswa kodaka oluxubeneyo olomileyo, luphumelele ukutsiba kwishishini le-cellulose ether.


Ixesha lokuposa: Feb-06-2023
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