Focus on Cellulose ethers

I-cellulose ether eguquliwe usimende slurry

I-cellulose ether eguquliwe usimende slurry

 

Umthelela wesakhiwo samangqamuzana esihlukile se-non-ionic cellulose ether esakhiweni sezimbotshana zodaka lukasimende wacwaningwa ngokuhlolwa kokuminyana kokusebenza kanye nokubhekwa kwesakhiwo sezimbotshana ezincane kakhulu nezincane kakhulu.Imiphumela ibonisa ukuthi i-nonionic cellulose ether ingakhuphula i-porosity ye-slurry kasimende.Uma i-viscosity ye-non-ionic cellulose ether modified slurry ifana, i-porosityi-hydroxyethyl cellulose ether(HEC) udaka olushintshiwe luncane kunalolo lwe-hydroxypropyl methyl cellulose ether (HPMC) kanye ne-methyl cellulose ether (MC) eguquliwe slurry.Ukuncipha kwe-viscosity/isisindo sengqamuzana esihlobene se-HPMC cellulose ether enokuqukethwe kweqembu okufanayo, kuba kuncane ukubumbana kodaka oluncibilikisiwe lukasimende.I-non-ionic cellulose ether inganciphisa ukungezwani kwendawo yesigaba soketshezi futhi yenze udaka lukasimende lube lula ukwenza amabhamuza.Ama-molecule e-non-ionic cellulose ether akhangiswe ngendlela eqondile kusixhumi esibonakalayo segesi-uketshezi lwamabhamuza, aphinde akhulise i-viscosity yesigaba se-slurry sikasimende futhi athuthukise ikhono le-slurry kasimende ukuzinzisa amabhamuza.

Amagama angukhiye:i-nonionic cellulose ether;Udaka lukasimende;Isakhiwo se-Pore;Isakhiwo samangqamuzana;Ukushuba kobuso;i-viscosity

 

I-nonionic cellulose ether (ngemuva kwalokhu ebizwa ngokuthi i-cellulose ether) inokujiya okuhle kakhulu nokugcinwa kwamanzi, futhi isetshenziswa kakhulu odakeni oluxubile olomile, ukhonkolo ozihlanganisayo kanye nezinye izinto ezintsha esekwe usimende.Ama-cellulose ether asetshenziswa ezintweni ezisekelwe kusimende ngokuvamile ahlanganisa i-methyl cellulose ether (MC), i-hydroxypropyl methyl cellulose ether (HPMC), i-hydroxyethyl methyl cellulose ether (HEMC) kanye ne-hydroxyethyl cellulose ether (HEC), phakathi kwayo i-HPMC ne-HEMC kuyizinto ezisetshenziswa kakhulu. .

I-cellulose ether ingathinta kakhulu ukwakheka kwembotshana ye-cement slurry.U-Pourchez et al., ngokuhlolwa okusobala kokuminyana, ukuhlolwa kosayizi wembotshana (indlela yokujova i-mercury) kanye nokuhlaziywa kwesithombe se-seM, kuphethe ngokuthi i-cellulose ether ingakhuphula isibalo sezimbotshana ezinobubanzi obungaba ngu-500nm kanye nezimbotshana ezinobubanzi obungaba ngu-50-250μm udaka lukasimende.Ngaphezu kwalokho, ngodaka lukasimende oluqinile, Ukusatshalaliswa kosayizi wembotshana wesisindo esiphansi samangqamuzana i-HEC eguquliwe usimende kufana nalokho kodaka lukasimende oluhlanzekile.Isamba sembotshana yembotshana yesisindo semolekyuli ephezulu ye-HEC eguquliwe usimende iphezulu kunaleyo yodaka lukasimende omsulwa, kodwa iphansi kunaleyo yodaka lukasimende oshintshiwe we-HPMC cishe nokungaguquguquki okufanayo.Ngokubuka kwe-SEM, uZhang et al.ithole ukuthi i-HEMC ingandisa kakhulu inani lezimbotshana ezinobubanzi obungaba ngu-0.1mm odakeni lukasimende.Baphinde bathola ngokuhlolwa komjovo we-mercury ukuthi i-HEMC ingakhuphula ngokuphawulekayo isamba sembotshana esiphelele kanye nesilinganiso sobubanzi bembotshana esiludaka lukasimende, okubangele ukwanda okukhulu kwenani lezimbotshana ezinkulu ezinobubanzi obungu-50nm ~ 1μm nezimbotshana ezinkulu ezinobubanzi obungaphezulu. kwe 1m.Kodwa-ke, inani lezimbotshana ezinobubanzi obungaphansi kuka-50nm lehliswe kakhulu.U-Saric-Coric et al.wayekholelwa ukuthi i-cellulose ether ingenza udaka lukasimende lube nezimbotshana futhi kuholele ekwandeni kwama-macropores.Jenni et al.ihlole ukuminyana kokusebenza futhi yanquma ukuthi ingxenyenamba yevolumu ye-pore ye-HEMC eguquliwe ye-cement mortar yayicishe ibe ngu-20%, kuyilapho udaka oluhlanzekile lukasimende luqukethe kuphela inani elincane lomoya.Silva et al.ithole ukuthi ngaphezu kweziqongo ezimbili eziku-3.9 nm kanye no-40 ~ 75nm njengodaka lukasimende oluhlanzekile, kwakukhona futhi iziqongo ezimbili ku-100 ~ 500nm nangaphezulu kuka-100μm ngokuhlolwa komjovo we-mercury.UMa Baoguo et al.ithole ukuthi i-cellulose ether yandisa isibalo sezimbotshana ezinhle ezinobubanzi obungaphansi kuka-1μm nezimbotshana ezinkulu ezinobubanzi obukhulu kuno-2μm odakeni lukasimende ngokuhlolwa komjovo we-mercury.Ngokuqondene nesizathu sokuthi i-cellulose ether yandisa i-porosity ye-slurry kasimende, ngokuvamile kunenkolelo yokuthi i-cellulose ether inomsebenzi ongaphezulu, izocebisa emoyeni nasemanzini esibonakalayo, yenze ifilimu, ukuze kuqiniswe ama-bubbles ku-slurry kasimende.

Ngokuhlaziywa kwezincwadi ezingenhla, kungabonakala ukuthi umphumela we-cellulose ether esakhiweni se-pore sezinto ezisekelwe usimende uthole ukunakwa okukhulu.Kodwa-ke, kunezinhlobo eziningi ze-cellulose ether, uhlobo olufanayo lwe-cellulose ether, isisindo salo samangqamuzana, okuqukethwe kweqembu kanye neminye imingcele yesakhiwo samangqamuzana nakho kuhluke kakhulu, futhi abacwaningi basekhaya nabangaphandle ekukhethweni kwe-cellulose ether kunqunyelwe kuphela ekusetshenzisweni kwabo ngokulandelanayo. inkambu, ukuntuleka kokumelela, isiphetho asinakugwenywa "ukweqa ngokweqile", ukuze incazelo ye-cellulose ether mechanism ingajulile ngokwanele.Kuleli phepha, umphumela we-cellulose ether enesakhiwo samangqamuzana ahlukene esakhiweni sezimbotshana zodaka lukasimende wacwaningwa ngokuhlolwa kokuminyana okusobala nokubhekwa kwesakhiwo sembotshana encanyana kanye nencanyana encane.

 

1. Hlola

1.1 Izinto ezingavuthiwe

Usimende kwakungusimende we-P·O 42.5 ojwayelekile wase-Portland owakhiwe yi-Huaxin Cement Co., LTD., lapho ukwakheka kwamakhemikhali kukalwa nge-AXIOS Ad-Vanced wavelength dispersion-type X-ray fluorescence spectrometer (PANa — lytical, Netherlands), futhi ukwakheka kwesigaba kwalinganiselwa ngendlela ye-Bogue.

I-Cellulose ether ikhethe izinhlobo ezine ze-ether cellulose ether, ngokulandelana i-methyl cellulose ether (MC), i-hydroxypropyl methyl cellulose ether (HPMC1, HPMC2) ne-hydroxyethyl cellulose ether (HEC), isakhiwo se-molecular HPMC1 kanye ne-HPMC2 efanayo, kodwa i-viscosity incane kakhulu kune-HPMC2. , Okusho ukuthi, i-molecular mass ye-HPMC1 incane kakhulu kunaleyo ye-HPMC2.Ngenxa yezakhiwo ezifanayo ze-hydroxyethyl methyl cellulose ether (HEMc) ne-HPMC, ama-HEMC awakhethwanga kulolu cwaningo.Ukugwema umthelela womswakamo emiphumeleni yokuhlolwa, wonke ama-cellulose ether abhakwa ku-98℃ amahora angu-2 ngaphambi kokusetshenziswa.

I-viscosity ye-cellulose ether ihlolwe yi-NDJ-1B rotary viscosimeter (i-Shanghai Changji Company).Ukugxiliswa kwesixazululo sokuhlola (isilinganiso sobuningi be-cellulose ether namanzi) sasingu-2.0%, izinga lokushisa lalingu-20℃, futhi izinga lokuzungezisa lalingu-12r/min.Ukungezwani okungaphezulu kwe-cellulose ether kwahlolwa ngendlela yokukhala.Ithuluzi lokuhlola bekungu-JK99A i-tensiometer ezenzakalelayo (i-Shanghai Zhongchen Company).Ukugxila kwesixazululo sokuhlola kwaba ngu-0.01% kanti izinga lokushisa lalingu-20 ℃.Okuqukethwe kweqembu le-cellulose ether kunikezwa umkhiqizi.

Ngokusho kwe-viscosity, ukungezwani kwendawo kanye nokuqukethwe kweqembu le-cellulose ether, lapho ukuhlushwa kwesisombululo kungu-2.0%, isilinganiso se-viscosity se-HEC ne-HPMC2 isisombululo singu-1: 1.6, kanye ne-viscosity ratio ye-HEC ne-MC isisombululo ngu-1: 0.4, kodwa kulokhu kuhlolwa, isilinganiso samanzi nosimende singu-0.35, isilinganiso esiphezulu sikasimende singu-0.6%, isilinganiso sesisindo se-cellulose ether emanzini sicishe sibe ngu-1.7%, singaphansi kuka-2.0%, kanye nomphumela we-synergistic we-slurry kasimende ku-viscosity, Umehluko we-viscosity we-HEC, HPMC2 noma i-MC modified usimende slurry mncane.

Ngokusho kwe-viscosity, ukungezwani kwendawo kanye nokuqukethwe kweqembu kwe-cellulose ether, ukungezwani kwendawo ye-cellulose ether ngayinye kuhlukile.I-cellulose ether inawo womabili amaqembu e-hydrophilic (amaqembu e-hydroxyl ne-ether) kanye namaqembu e-hydrophobic (i-methyl ne-glucose carbon ring), i-surfactant.I-cellulose ether ihlukile, uhlobo nokuqukethwe kwamaqembu e-hydrophilic kanye ne-hydrophobic kuhlukile, okuholela ekucindezelekeni okuhlukile kwendawo.

1.2 Izindlela zokuhlola

Izinhlobo eziyisithupha zodaka lukasimende zalungiswa, okuhlanganisa udaka lukasimende oluhlanzekile, i-cellulose ether emine (MC, HPMCl, HPMC2 kanye ne-HEC) udaka lukasimende olulungisiwe ngo-0.60% wesilinganiso sikasimende kanye ne-HPMC2 eguquliwe usimende slurry ngesilinganiso sikasimende esingu-0.05%.Ref, MC — 0.60, HPMCl — 0.60, Hpmc2-0.60.I-HEC 1-0.60 kanye ne-hpMC2-0.05 ikhombisa ukuthi isilinganiso samanzi nosimende singu-0.35.

Udaka lukasimende kuqala ngokuhambisana ne-GB/T 17671 1999 “indlela yokuhlola amandla kasimende (indlela ye-ISO)” eyenziwe yaba yibhulokhi yokuhlola yama-prisms engu-40mm×40mm×160mm, ngaphansi kwesimo se-20℃ esivalwe ukuphulukisa i-28d.Ngemva kokukala nokubala ukuminyana kwayo okusobala, yaqhephuka ngesando esincane, futhi isimo sembobo enkulu yengxenye emaphakathi yebhulokhi yokuhlola yabonwa futhi yathwetshulwa ngekhamera yedijithali.Ngesikhathi esifanayo, izingcezu ezincane ze-2.5 ~ 5.0mm zathathwa ukuze zibonwe ngesibonakhulu esibonakalayo (i-HIROX isibonakhulu sevidiyo enezinhlangothi ezintathu) nokuskena isibonakhulu se-electron (JSM-5610LV).

 

2. Imiphumela yokuhlolwa

2.1 Ukuminyana okusobala

Ngokokuminyana okusobala kodaka lukasimende olulungiswe ama-ether e-cellulose ahlukene, (1) ukuminyana okusobala kodaka lukasimende kuphezulu kakhulu, okungu-2044 kg/m³;Ukuminyana okusobala kwezinhlobo ezine ze-cellulose ether eguquliwe ye-cellulose ngesilinganiso sikasimende esingu-0.60% kwakungu-74% ~ 88% walelo lodaka lukasimende oluhlanzekile, okubonisa ukuthi i-cellulose ether ibangele ukwanda kwe-porosity kasimende slurry.(2) Uma isilinganiso sikasimende kusimende singu-0.60%, umphumela wama-ether e-cellulose ahlukene ku-porosity kasimende oludaka uhluke kakhulu.I-viscosity ye-HEC, HPMC2 kanye ne-MC modified simende slurry iyafana, kodwa ukuminyana okusobala kwe-HEC modified simende slurry kuphezulu kakhulu, okubonisa ukuthi i-porosity ye-HEC modified simende slurry incane kunaleyo ye-HPMc2 kanye ne-Mc modified usimende slurry enodaka olufanayo lwe-visco. .I-HPMc1 kanye ne-HPMC2 inokuqukethwe kweqembu okufanayo, kodwa i-viscosity ye-HPMCl iphansi kakhulu kunaleyo ye-HPMC2, futhi ukuminyana okusobala kodaka lukasimende oshintshiwe lwe-HPMCl kuphezulu kakhulu kunokweludaka lukasimende olungisiwe lwe-HPMC2, okubonisa ukuthi lapho okuqukethwe kweqembu kufana. , i-viscosity ye-cellulose ether iyancipha, i-porosity ye-slurry kasimende eshintshiwe iyancipha.(3) Uma isilinganiso sikasimende kusimende sisincane kakhulu (0.05%), ukuminyana okubonakalayo kodaka lukasimende oshintshiwe nge-HPMC2 ngokuyisisekelo kusondelene nokuludaka oluhlanzekile lukasimende, okubonisa ukuthi umphumela we-cellulose ether ekuqineni kukasimende. i-slurry incane kakhulu.

2.2 Izimbotshana zeMacroscopic

Ngokusho kwezithombe zesigaba se-cellulose ether eguquliwe usimende oludaka oluthathwe ikhamera yedijithali, i-slurry ye-cement ehlanzekile iminyene kakhulu, cishe awekho ama-pores abonakalayo;Izinhlobo ezine ze-cellulose ether eguquliwe slurry enesilinganiso sikasimende esingu-0.60% zonke zinezimbotshana eziningi ze-macroscopic, okubonisa ukuthi i-cellulose ether iholela ekwandeni kodaka lukasimende.Ngokufanayo nemiphumela yokuhlolwa kokuminyana okusobala, umphumela wezinhlobo ezahlukene ze-cellulose ether nokuqukethwe ku-porosity ye-slurry kasimende uhluke kakhulu.I-viscosity ye-HEC, HPMC2 kanye ne-MC modified slurry iyafana, kodwa i-porosity ye-HEC modified slurry incane kunaleyo ye-HPMC2 kanye ne-MC modified slurry.Nakuba i-HPMC1 ne-HPMC2 inokuqukethwe kweqembu okufanayo, i-HPMC1 eguquliwe i-slurry ene-viscosity ephansi ine-porosity encane.Uma isilinganiso sikasimende kuya kusimende se-HPMC2 eguquliwe slurry sincane kakhulu (0.05%), inani lezimbotshana ezinkulu liyakhuphuka kancane kunalelo lodaka oluhlanzekile lukasimende, kodwa linciphe kakhulu kunalelo le-HPMC2 eguquliwe ngodaka olunosimende ongu-0.60% kuya -simende isilinganiso.

2.3 Imbotshana encane

4. Isiphetho

(1) I-cellulose ether ingakhuphula i-porosity ye-slurry kasimende.

(2) Umphumela we-cellulose ether ku-porosity kasimende slurry enezinhlaka ezahlukene zesakhiwo samangqamuzana uhlukile: uma i-viscosity ye-cellulose ether eguquliwe usimende slurry ifana, i-porosity ye-HEC eguquliwe usimende slurry incane kune-HPMC ne-MC eshintshiwe. udaka lukasimende;Ukuncipha kwe-viscosity/isisindo sengqamuzana esihlobene se-HPMC cellulose ether enokuqukethwe kweqembu okufanayo, kwehlisa ukujula kodaka oluncibilikisiwe lukasimende.

(3) Ngemva kokwengeza i-cellulose ether odongeni lukasimende, ukungezwani okungaphezulu kwesigaba soketshezi kuyancishiswa, ukuze udaka lukasimende lube lula ukwenza amabhamuza i-cellulose ether ama-molecule adsorption aqondisayo ku-bubble gas-liquid interface, ngcono amandla kanye nokuqina i-bubble liquid adsorption kusixhumi esibonakalayo se-bubble gas-liquid, ithuthukisa amandla efilimu ye-bubble liquid futhi iqinise ikhono lodaka oluqinile lokuzinzisa ibhamuza.


Isikhathi sokuthumela: Feb-05-2023
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