Focus on Cellulose ethers

Umthelela wezinga lokushisa elizungezile ekusebenzeni kwegypsum ye-cellulose ether eshintshiwe

Umthelela wezinga lokushisa elizungezile ekusebenzeni kwegypsum ye-cellulose ether eshintshiwe

Ukusebenza kwe-gypsum eguquliwe ye-cellulose ether emazingeni okushisa ahlukene e-ambient kuhluke kakhulu, kodwa indlela yayo ayicacile. Imiphumela ye-cellulose ether kumapharamitha we-rheological kanye nokugcinwa kwamanzi kwe-gypsum slurry emazingeni okushisa ahlukene azungezile kwafundwa. Idayamitha ye-hydrodynamic ye-cellulose ether esigabeni soketshezi ikalwe ngendlela yokuhlakazeka kokukhanya okuguquguqukayo, futhi indlela yethonya yahlolwa. Imiphumela ibonisa ukuthi i-cellulose ether inomphumela omuhle wokugcina amanzi kanye nokuqina ku-gypsum. Ngokukhula kokuqukethwe kwe-cellulose ether, i-viscosity ye-slurry iyanda futhi amandla okugcina amanzi ayanda. Kodwa-ke, ngokukhuphuka kwezinga lokushisa, amandla okugcina amanzi e-gypsum slurry eguquliwe ayancipha ngezinga elithile, futhi imingcele ye-rheological nayo iyashintsha. Uma kucatshangelwa ukuthi i-cellulose ether colloid association ingafinyelela ukugcinwa kwamanzi ngokuvimbela isiteshi sokuthutha amanzi, ukunyuka kwezinga lokushisa kungase kuholele ekuhlakazweni kwenhlangano enkulu yevolumu ekhiqizwa i-cellulose ether, ngaleyo ndlela kunciphise ukugcinwa kwamanzi nokusebenza kokusebenza kwe-gypsum eguquliwe.

Amagama angukhiye:i-gypsum; I-cellulose ether; Izinga lokushisa; Ukugcinwa kwamanzi; i-rheology

 

0. Isingeniso

I-Gypsum, njengohlobo lwempahla enobungani bemvelo enokwakhiwa okuhle nezakhiwo zomzimba, isetshenziswa kabanzi kumaphrojekthi wokuhlobisa. Ekusetshenzisweni kwezinto ezisekelwe ku-gypsum, i-ejenti yokugcina amanzi ivame ukungezwa ukuze kulungiswe udaka ukuze kuvinjelwe ukulahlekelwa kwamanzi ohlelweni lwe-hydration kanye nokuqina. I-Cellulose ether iyona evame kakhulu ukugcina amanzi okwamanje. Ngoba i-ionic CE izosabela nge-Ca2+, ngokuvamile isebenzisa i-non-ionic CE, njengalokhu: i-hydroxypropyl methyl cellulose ether, i-hydroxyethyl methyl cellulose ether ne-methyl cellulose ether. Kubalulekile ukutadisha izakhiwo ze-cellulose ether modified gypsum ukuze kusetshenziswe kangcono i-gypsum kubunjiniyela bokuhlobisa.

I-Cellulose ether iyinhlanganisela yamangqamuzana ephezulu ekhiqizwa ukusabela kwe-alkali cellulose kanye ne-etherifying agent ngaphansi kwezimo ezithile. I-nonionic cellulose ether esetshenziswa kubunjiniyela bokwakha inokuhlakazeka okuhle, ukugcinwa kwamanzi, ukubopha kanye nomthelela wokujiya. Ukwengezwa kwe-cellulose ether kunomthelela osobala kakhulu ekugcinweni kwamanzi e-gypsum, kodwa amandla okugoba namandla acindezelayo we-gypsum eqinile yomzimba nawo ayancipha kancane ngokwanda kwenani elingeziwe. Lokhu kungenxa yokuthi i-cellulose ether inomphumela othile wokufaka umoya, okuzokwethula ama-bubbles ohlelweni lokuxutshwa kwe-slurry, ngaleyo ndlela kunciphise izakhiwo zemishini zomzimba oqinile. Ngesikhathi esifanayo, i-cellulose ether eningi izokwenza ingxube ye-gypsum inamathele kakhulu, okuholela ekusebenzeni kwayo kokwakhiwa.

Inqubo ye-hydration ye-gypsum ingahlukaniswa ngezinyathelo ezine: ukuchithwa kwe-calcium sulfate hemihydrate, i-crystallization nucleation ye-calcium sulfate dihydrate, ukukhula kwe-nucleus ye-crystalline kanye nokwakheka kwesakhiwo se-crystalline. Enqubweni ye-hydration ye-gypsum, iqembu elisebenzayo le-hydrophilic le-cellulose ether elikhangisa ebusweni bezinhlayiya ze-gypsum lizolungisa ingxenye yama-molecule wamanzi, ngaleyo ndlela libambezele inqubo ye-nucleation ye-gypsum hydration nokwandisa isikhathi sokusetha se-gypsum. Ngokubuka kwe-SEM, uMroz uthole ukuthi nakuba ukuba khona kwe-cellulose ether kubambezele ukukhula kwamakristalu, kodwa kwandise ukugqagqana nokuhlanganiswa kwamakristalu.

I-Cellulose ether iqukethe amaqembu e-hydrophilic ukuze ibe ne-hydrophilicity ethile, i-polymer chain chain ixhumene nomunye nomunye ukuze ibe ne-viscosity ephezulu, ukusebenzisana kokubili kwenza i-cellulose ibe nomphumela omuhle wokugcinwa kwamanzi okuqina ekuxubeni kwe-gypsum. U-Bulichen wachaza indlela yokugcina amanzi ye-cellulose ether kusimende. Ekuxubeni okuphansi, i-cellulose ether i-adsorb kusimende ukuze imunce amanzi e-intramolecular futhi ihambisane nokuvuvukala ukuze kuzuzwe ukugcinwa kwamanzi. Ngalesi sikhathi, ukugcinwa kwamanzi kubi. Isilinganiso esiphezulu, i-cellulose ether izokwakha amakhulu ama-nanometers kuma-microns ambalwa we-polymer ye-colloidal, ivimbele ngokuphumelelayo uhlelo lwejeli emgodini, ukuze kuzuzwe ukugcinwa kwamanzi okusebenzayo. Indlela yokusebenza ye-cellulose ether ku-gypsum iyafana naleyo ekusimende, kodwa ukugxila okuphezulu kwe-SO42 esigabeni soketshezi lwe-gypsum slurry kuzowenza buthaka umphumela wokugcina amanzi we-cellulose.

Ngokusekelwe kokuqukethwe okungenhla, kungatholakala ukuthi ucwaningo lwamanje nge-cellulose ether modified gypsum lugxile kakhulu kwinqubo ye-hydration ye-cellulose ether kumxube we-gypsum, izakhiwo zokugcina amanzi, izakhiwo zemishini kanye ne-microstructure yomzimba oqinile, kanye nendlela ye-cellulose ether. ukugcinwa kwamanzi. Nokho, ucwaningo lokusebenzelana phakathi kwe-cellulose ether ne-gypsum slurry ezingeni lokushisa eliphezulu alukanele. Isixazululo samanzi se-cellulose ether sizofaka i-gelatin ezingeni lokushisa elithile. Njengoba izinga lokushisa likhuphuka, i-viscosity ye-cellulose ether solution yamanzi izokwehla kancane kancane. Lapho izinga lokushisa le-gelatinization lifinyelelwa, i-cellulose ether izoncibilika ibe ijeli emhlophe. Isibonelo, ekwakhiweni kwehlobo, izinga lokushisa elizungezile liphezulu, izakhiwo zejeli ezishisayo ze-cellulose ether zizoholela ekushintsheni ekusebenzeni kwe-gypsum slurry eguquliwe. Lo msebenzi uhlola umthelela wokwenyuka kwezinga lokushisa ekusebenzeni kwe-cellulose ether eshintshiwe yezinto zegypsum ngokuhlolwa okuhleliwe, futhi unikeza isiqondiso sokusetshenziswa okungokoqobo kwegypsum ye-cellulose ether modified gypsum.

 

1. Isivivinyo

1.1 Izinto ezingavuthiwe

I-Gypsum iwuhlobo lwe-β-gypsum yokwakha yemvelo ehlinzekwa yi-Beijing Ecological Home Group.

I-cellulose ether ekhethwe ku-Shandong Yiteng Group hydroxypropyl methyl cellulose ether, imininingwane yomkhiqizo yama-75,000 mPa·s, 100,000 mPa·s kanye no-200000mPa·s, izinga lokushisa le-gelation ngaphezu kuka-60 ℃. I-citric acid ikhethwe njenge-gypsum retarder.

1.2 Ukuhlola I-Rheology

Ithuluzi lokuhlola i-rheological elisetshenzisiwe kwakuyi-RST⁃CC rheometer ekhiqizwe yi-BROOKFIELD USA. Amapharamitha we-rheological afana ne-plastic viscosity kanye ne-hear stress ye-shear ye-gypsum slurry anqunywe isiqukathi sesampula se-MBT⁃40F⁃0046 kanye ne-CC3⁃40 rotor, futhi idatha yacutshungulwa isofthiwe ye-RHE3000.

Izici zengxube ye-gypsum zihambisana nokuziphatha kwe-rheological ye-Bingham fluid, evame ukufundwa kusetshenziswa imodeli ye-Bingham. Kodwa-ke, ngenxa ye-pseudoplasticity ye-cellulose ether engezwe ku-gypsum elungiswe nge-polymer, ingxube ye-slurry ngokuvamile iveza impahla ethile yokugunda i-shear. Kulokhu, imodeli ye-Bingham (M⁃B) elungisiwe ingachaza kangcono ijika le-rheological yegypsum. Ukuze ufunde ngokuguqulwa kwe-shear yegypsum, lo msebenzi futhi usebenzisa imodeli ye-Herschel⁃Bulkley (H⁃B).

1.3 Ukuhlolwa kokugcina amanzi

Inqubo yokuhlola ibhekisela ku-GB/T28627⁃2012 Plastering Plaster. Ngesikhathi sokuhlolwa kwezinga lokushisa njengokuguquguquka, i-gypsum yashiswa kusengaphambili i-1h kusengaphambili ekushiseni okuhambisanayo kuhhavini, futhi amanzi axubile asetshenziswe ekuhloleni ashiswe kuqala ngo-1h ekushiseni okuhambisanayo ekugezeni kwamanzi okushisa okungaguquki, kanye nethuluzi elisetshenzisiwe. yashiswa ngaphambili.

1.4 Ukuhlolwa kobubanzi be-Hydrodynamic

I-hydrodynamic diameter (D50) ye-HPMC polymer association esigabeni soketshezi ikalwe kusetshenziswa ukuhlaziya usayizi wezinhlayiyana ezihlakazekayo (i-Malvern Zetasizer NanoZS90).

 

2. Imiphumela kanye nengxoxo

2.1 Izakhiwo ze-Rheological ze-HPMC modified gypsum

I-viscosity ebonakalayo isilinganiso sokugunda kwe-shear nezinga le-shear elisebenza oketshezini futhi iyipharamitha ekhombisa ukugeleza koketshezi olungewona olwase-Newton. I-viscosity esobala ye-gypsum slurry eguquliwe ishintshile nokuqukethwe kwe-cellulose ether ngaphansi kokucaciswa okuthathu okuhlukene (75000mPa·s, 100,000mpa ·s kanye no-200000mPa·s). Izinga lokushisa lokuhlola lalingu-20 ℃. Uma izinga le-shear le-rheometer liyi-14min-1, kungatholakala ukuthi i-viscosity ye-gypsum slurry iyanda ngokunyuka kokufakwa kwe-HPMC, futhi ukuphakama kwe-viscosity ye-HPMC, kuyanda kwe-viscosity ye-gypsum slurry eguquliwe. Lokhu kukhombisa ukuthi i-HPMC inomphumela osobala wokujiya kanye ne-viscosification ku-gypsum slurry. I-Gypsum slurry ne-cellulose ether yizinto ezine-viscosity ethile. Engxubeni ye-gypsum eguquliwe, i-cellulose ether iyakhangiswa ebusweni bemikhiqizo ye-gypsum hydration, futhi inethiwekhi eyakhiwe nge-cellulose ether kanye nenethiwekhi eyakhiwe yingxube ye-gypsum iyahlanganiswa, okuholela "kumphumela we-superposition", okuthuthukisa kakhulu i-viscosity yonke okuguquliwe okusekelwe ku-gypsum.

I-shear ⁃ amajika okucindezeleka e-gypsum emsulwa (G⁃H) ne-modified gypsum (G⁃H) yokunamathisela efakwe nge-75000mPa· s-HPMC, njengoba kucatshangwa kusukela kumodeli ebuyekeziwe ye-Bingham (M⁃B). Kungatholakala ukuthi ngokunyuka kwezinga le-shear, ukucindezeleka kwe-shear kwengxube nakho kuyanda. I-viscosity yepulasitiki (ηp) kanye nenani le-shear stress (τ0) ye-gypsum emsulwa kanye negypsum eshintshiwe ye-HPMC emazingeni okushisa ahlukene ayatholakala.

Kusuka ku-viscosity yepulasitiki (ηp) kanye nokucindezeleka kwe-shear kwesivuno (τ0) amanani we-gypsum ehlanzekile kanye ne-HPMC eguquliwe e-gypsum emazingeni okushisa ahlukene, kungabonakala ukuthi ukucindezeleka kwesivuno se-HPMC modified gypsum kuzokwehla ngokuqhubekayo ngokunyuka kwezinga lokushisa, kanye nesivuno. ukucindezeleka kuzokwehla ngo-33% ku-60 ℃ uma kuqhathaniswa no-20 ℃. Ngokubheka ijika le-viscosity yepulasitiki, kungatholakala ukuthi i-viscosity yepulasitiki ye-gypsum slurry eguquliwe nayo iyancipha ngokunyuka kwezinga lokushisa. Kodwa-ke, ukucindezeleka kwesivuno kanye ne-viscosity yepulasitiki ye-gypsum slurry ehlanzekile ikhuphuka kancane ngokunyuka kwezinga lokushisa, okubonisa ukuthi ukuguqulwa kwemingcele ye-rheological ye-HPMC eguquliwe ye-gypsum slurry enqubweni yokwanda kwezinga lokushisa kubangelwa ukuguqulwa kwezakhiwo ze-HPMC.

Inani lengcindezi yesivuno le-gypsum slurry libonisa inani eliphakeme lokucindezelwa kwe-shear lapho udaka lumelana nokuguqulwa kwe-shear. Uma likhulu inani lokucindezeleka kwesivuno, i-gypsum slurry ingaba namandla kakhulu. I-viscosity yepulasitiki ibonisa izinga lokuguqulwa kwe-gypsum slurry. Uma i-viscosity yepulasitiki inkulu, isikhathi sokuguqulwa kwe-shear se-slurry sizoba side. Sengiphetha, imingcele emibili ye-rheological ye-HPMC eguquliwe ye-gypsum slurry iyancipha ngokusobala ngokunyuka kwezinga lokushisa, futhi umphumela wokujiya we-HPMC ku-gypsum slurry uba buthaka.

Ukugundwa kwe-shear kwe-slurry kubhekisela ekujikeni kwe-shear noma umphumela wokunciphisa ukugunda oboniswa ukushelela lapho kugundwa ngamandla. Umphumela we-shear deformation we-slurry ungahlulelwa ngenkomba ye-pseudoplastic n etholwe ejikeni elifanelekile. Uma n < 1, i-gypsum slurry ibonisa ukugunda kwe-shear, futhi izinga lokunciphisa i-gypsum slurry liba phezulu ngokuncipha kwe-n. Lapho n > 1, udaka lwegypsum lubonisa ukujiya kwe-shear, futhi izinga lokujiya le-gypsum slurry lenyuka ngokunyuka kwe-n. Amajika e-Rheological we-HPMC eshintshiwe ye-gypsum slurry kumazinga okushisa ahlukene asekelwe ekulinganisweni kwemodeli ye-Herschel⁃Bulkley (H⁃B), ngaleyo ndlela athole inkomba ye-pseudoplastic n ye-HPMC eguquliwe ye-gypsum slurry.

Ngokusho kwe-pseudoplastic index n ye-HPMC modified gypsum slurry, ukuwohloka kwe-shear ye-gypsum slurry exutshwe ne-HPMC kuwukuphungula kwe-shear, futhi inani le-n liyakhula kancane kancane ngokunyuka kwezinga lokushisa, okukhombisa ukuthi ukuziphatha kokugunda kwe-shear kwegypsum eguquliwe ye-HPMC kuzokwehla. ube buthaka ngezinga elithile lapho uhlaselwe izinga lokushisa.

Ngokusekelwe ezinguqukweni ezisobala ze-viscosity ze-gypsum slurry eguquliwe enesilinganiso sokugunda esibalwe kusukela kudatha yokucindezeleka kwe-shear engu-75000 mPa· HPMC emazingeni okushisa ahlukene, kungatholwa ukuthi i-viscosity yepulasitiki ye-gypsum slurry eguquliwe yehla ngokushesha ngokwenyuka kwezinga lokugunda, eqinisekisa umphumela ofanelekile wemodeli ye-H⁃B. I-gypsum slurry eguquliwe ibonise izici zokunciphisa i-shear. Ngokunyuka kwezinga lokushisa, i-viscosity ebonakalayo yengxube iyancipha ngezinga elithile ngesilinganiso esiphansi se-shear, okubonisa ukuthi umphumela wokunciphisa i-shear we-gypsum slurry eguquliwe iyancipha.

Ekusetshenzisweni kwangempela kwe-gypsum putty, i-gypsum slurry iyadingeka ukuze kube lula ukuwohloka enqubweni yokuhlikihla futhi ihlale izinzile ekuphumuleni, okudinga i-gypsum slurry ukuze ibe nezici ezinhle zokunciphisa i-shear, futhi ukuguqulwa kwe-shear kwe-gypsum eguquliwe ye-HPMC akuvamile ngezinga elithile, elingahambisani nokwakhiwa kwezinto ze-gypsum. I-viscosity ye-HPMC ingenye yemingcele ebalulekile, futhi isizathu esiyinhloko sokuthi idlala indima yokuqina ukuze kuthuthukiswe izici eziguquguqukayo zokugeleza kokuxuba. I-Cellulose ether ngokwayo inezici zejeli elishisayo, i-viscosity yesisombululo sayo se-aqueous iyancipha kancane kancane njengoba izinga lokushisa likhuphuka, futhi ijeli elimhlophe likhuphuka lapho lifinyelela izinga lokushisa le-gelation. Ukuguqulwa kwemingcele ye-rheological ye-cellulose ether eguquliwe ye-gypsum enezinga lokushisa ihlobene eduze noshintsho lwe-viscosity, ngoba umphumela wokuqina uwumphumela we-superposition ye-cellulose ether kanye ne-slurry exubile. Kubunjiniyela obusebenzayo, umthelela wokushisa kwemvelo ekusebenzeni kwe-HPMC kufanele ucatshangelwe. Isibonelo, izinga lokushisa lezinto zokusetshenziswa kufanele lilawulwe ekushiseni okuphezulu ehlobo ukugwema ukusebenza okungekuhle kwe-gypsum eguquliwe okubangelwa izinga lokushisa eliphezulu.

2.2 Ukugcinwa kwamanzi kweI-HPMC eguquliwe ye-gypsum

Ukugcinwa kwamanzi kwe-gypsum slurry elungiswe ngezicaciso ezintathu ezahlukene ze-cellulose ether kuyashintshwa ngejika lomthamo. Ngokukhuphuka komthamo we-HPMC, izinga lokugcinwa kwamanzi kwe-gypsum slurry liyathuthuka kakhulu, futhi inkambiso yokwanda iba izinzile lapho umthamo we-HPMC ufinyelela ku-0.3%. Ekugcineni, izinga lokugcinwa kwamanzi kwe-gypsum slurry lizinzile ku-90% ~ 95%. Lokhu kubonisa ukuthi i-HPMC inomphumela osobala wokugcina amanzi ekunamathiseleni kwamatshe, kodwa umphumela wokugcina amanzi awuthuthukisiwe kakhulu njengoba umthamo uqhubeka nokukhula. Ukucaciswa okuthathu komehluko wezinga lokugcinwa kwamanzi kwe-HPMC akukukhulu, isibonelo, uma okuqukethwe kungu-0.3%, ububanzi bezinga lokugcinwa kwamanzi ngu-5%, ukuchezuka okujwayelekile kungu-2.2. I-HPMC ene-viscosity ephezulu kakhulu ayilona izinga eliphezulu lokugcinwa kwamanzi, futhi i-HPMC ene-viscosity ephansi ayilona izinga lokugcina amanzi eliphansi kakhulu. Kodwa-ke, uma kuqhathaniswa ne-gypsum ehlanzekile, izinga lokugcinwa kwamanzi le-HPMC emithathu ye-gypsum slurry lithuthukisiwe kakhulu, futhi izinga lokugcinwa kwamanzi le-gypsum eguquliwe ku-0.3% okuqukethwe likhuphuke ngo-95%, 106%, 97% uma liqhathaniswa ne iqembu lokulawula elingenalutho. I-cellulose ether ngokusobala ingathuthukisa ukugcinwa kwamanzi kwe-gypsum slurry. Ngokukhula kokuqukethwe kwe-HPMC, izinga lokugcinwa kwamanzi kwe-HPMC eshintshiwe ye-gypsum slurry ene-viscosity ehlukile kancane kancane ifinyelela endaweni yokugcwala. I-10000mPa·sHPMC ifinyelele endaweni yokugcwala ku-0.3%, 75000mPa·s kanye ne-20000mPa·s HPMC ifinyelele endaweni yokugcwala ku-0.2%. Imiphumela ibonisa ukuthi ukugcinwa kwamanzi okungu-75000mPa·s HPMC okushintshiwe kwegypsum kuyashintsha nezinga lokushisa ngaphansi komthamo ohlukile. Ngokuncipha kwezinga lokushisa, izinga lokugcina amanzi le-gypsum eshintshiwe ye-HPMC liyehla kancane kancane, kuyilapho izinga lokugcinwa kwamanzi e-gypsum ehlanzekile ngokuyisisekelo lihlala lingashintshile, okubonisa ukuthi ukunyuka kwezinga lokushisa kwenza buthaka umphumela wokugcina amanzi we-HPMC ku-gypsum. Izinga lokugcinwa kwamanzi le-HPMC lehle ngo-31.5% lapho izinga lokushisa lenyuka lisuka ku-20 ℃ laya ku-40℃. Lapho izinga lokushisa likhuphuka lisuka ku-40℃ liye ku-60℃, izinga lokugcinwa kwamanzi le-HPMC modified gypsum ngokuyisisekelo liyafana nalelo legypsum emsulwa, okubonisa ukuthi i-HPMC ilahlekelwe umphumela wokuthuthukisa ukugcinwa kwamanzi egypsum ngalesi sikhathi. U-Jian Jian no-Wang Peiming bahlongoze ukuthi i-cellulose ether ngokwayo ine-gel eshisayo, ukushintsha kwezinga lokushisa kuzoholela ekushintsheni kwe-viscosity, i-morphology kanye nokukhangisa kwe-cellulose ether, okuzoholela ekushintsheni ekusebenzeni kwe-slurry mix. U-Bulichen uphinde wathola ukuthi i-viscosity eguquguqukayo yezixazululo zikasimende eziqukethe i-HPMC yehla ngokukhuphuka kwezinga lokushisa.

Ukuguqulwa kokugcinwa kwamanzi kwengxube ebangelwa ukwanda kwezinga lokushisa kufanele kuhlanganiswe nendlela ye-cellulose ether. U-Bulichen wachaza indlela i-cellulose ether engagcina ngayo amanzi kusimende. Ezinhlelweni ezisekelwe kusimende, i-HPMC ithuthukisa izinga lokugcinwa kwamanzi oludaka ngokunciphisa ukungeneka “kwekhekhe lokuhlunga” elakhiwe uhlelo lukasimende. Ukuhlushwa okuthile kwe-HPMC esigabeni se-liquid kuzokwakha ama-nanometers angamakhulu ambalwa kuma-microns ambalwa we-colloidal association, lokhu kunevolumu ethile yesakhiwo se-polymer kungaxhuma ngokuphumelelayo isiteshi sokudlulisa amanzi ekuxubeni, kunciphise ukufinyeleleka "kwekhekhe lokuhlunga", ukuze kuzuzwe ukugcinwa kwamanzi ngendlela efanele. I-Bulichen iphinde yabonisa ukuthi i-HPMCS ku-gypsum ibonisa indlela efanayo. Ngakho-ke, ucwaningo lwe-diameter ye-hydromechanical yenhlangano eyakhiwe yi-HPMC esigabeni se-liquid ingachaza umphumela we-HPMC ekugcinweni kwamanzi e-gypsum.

2.3 I-Hydrodynamic diameter ye-HPMC colloid association

Izinhlayiyana zokusabalalisa amajika okugxiliswa okuhlukile kwe-75000mPa·s HPMC esigabeni soketshezi, namajika okusabalalisa izinhlayiyana zokucaciswa okuthathu kwe-HPMC esigabeni soketshezi ekuhlanganiseni okungu-0.6%. Kungabonakala ejikeni lokusatshalaliswa kwezinhlayiyana le-HPMC lokucaciswa okuthathu esigabeni soketshezi lapho ukugxila kungu-0.6% ukuthi, ngokwanda kokuhlushwa kwe-HPMC, usayizi wezinhlayiyana zezinhlanganisela ezihlotshaniswayo ezakhiwe esigabeni se-liquid nazo ziyanda. Uma ukugxila kuphansi, izinhlayiya ezakhiwe yi-HPMC aggregation zincane, futhi ingxenye encane kuphela ye-HPMC ihlangana ibe yizinhlayiya ezingaba ngu-100nm. Uma ukugxila kwe-HPMC kungu-1%, kunenombolo enkulu yezinhlangano ze-colloidal ezinobubanzi be-hydrodynamic obungaba ngu-300nm, okuwuphawu olubalulekile lokunqwabelana kwamangqamuzana. Lesi sakhiwo se-polymerization "yevolumu enkulu" singavimba ngokuphumelelayo isiteshi sokudlulisa amanzi ekuxubeni, sinciphise "ukungena kwekhekhe", futhi ukugcinwa kwamanzi okuhambisanayo kwengxube ye-gypsum kulokhu kugxilwa nakho kukhulu kunama-90%. Amadayamitha we-hydromechanical we-HPMC anama-viscosity ahlukene esigabeni soketshezi ayafana ngokuyisisekelo, okuchaza izinga elifanayo lokugcinwa kwamanzi le-HPMC eshintshiwe ye-gypsum slurry enama-viscosity ahlukene.

Amajika okusabalalisa usayizi wezinhlayiyana we-75000mPa·s HPMC nokugxiliswa okungu-1% kumazinga okushisa ahlukene. Ngokukhuphuka kwezinga lokushisa, ukubola kwe-HPMC colloidal association kungatholakala ngokusobala. Ku-40℃, umthamo omkhulu we-300nm association wanyamalala ngokuphelele futhi wabola waba yizinhlayiya zevolumu encane engu-15nm. Ngokukhula okwengeziwe kwezinga lokushisa, i-HPMC iba yizinhlayiya ezincane, futhi ukugcinwa kwamanzi kwe-gypsum slurry kulahleka ngokuphelele.

Isimo sezakhiwo ze-HPMC ezishintshayo ngokukhuphuka kwezinga lokushisa saziwa nangokuthi izakhiwo zejeli elishisayo, umbono ojwayelekile okhona wukuthi ekushiseni okuphansi, ama-macromolecules e-HPMC ahlakazeka kuqala emanzini ukuze ahlakaze isixazululo, ama-molecule e-HPMC ekugxilweni okuphezulu azokwakha inhlangano enkulu yezinhlayiyana. . Lapho izinga lokushisa likhuphuka, i-hydration ye-HPMC iba buthaka, amanzi phakathi kwamaketanga aphuma kancane kancane, izinhlanganisela ezinkulu zenhlangano zihlakazwa kancane kancane zibe yizinhlayiya ezincane, i-viscosity yesisombululo iyancipha, futhi isakhiwo senethiwekhi ye-three-dimensional yakheka lapho i-gelation. izinga lokushisa liyafinyelelwa, futhi ijeli emhlophe iyawa.

U-Bodvik uthole ukuthi izakhiwo ze-microstructure kanye ne-adsorption ye-HPMC esigabeni soketshezi zishintshiwe. Kuhlanganiswe nethiyori ka-Bulichen ye-HPMC colloidal association evimba isiteshi sokuthutha samanzi anodaka, kwaphethwa ngokuthi ukwanda kwezinga lokushisa kuholele ekuhlakazweni kwe-HPMC colloidal association, okubangele ukwehla kokugcinwa kwamanzi kwe-gypsum eguquliwe.

 

3. Isiphetho

(1) I-Cellulose ether ngokwayo ine-viscosity ephezulu kanye nomphumela "we-superimposed" nge-gypsum slurry, edlala umphumela osobala wokujiya. Ezingeni lokushisa lasekamelweni, umphumela wokujiya uba sobala kakhulu ngokwanda kwe-viscosity kanye nomthamo we-cellulose ether. Kodwa-ke, ngokukhuphuka kwezinga lokushisa, i-viscosity ye-cellulose ether iyancipha, umphumela wayo wokuqina uyancipha, ukucindezeleka kwesivuno se-shear kanye ne-viscosity yepulasitiki ye-gypsum mix mix, i-pseudoplasticity iba buthaka, futhi impahla yokwakha iba yimbi kakhulu.

(2) I-Cellulose ether ithuthukise ukugcinwa kwamanzi e-gypsum, kodwa ngokwanda kwezinga lokushisa, ukugcinwa kwamanzi e-gypsum eguquliwe nakho kwehle kakhulu, ngisho naku-60℃ kuzolahlekelwa ngokuphelele umphumela wokugcinwa kwamanzi. Izinga lokugcinwa kwamanzi kwe-gypsum slurry lathuthukiswa kakhulu nge-cellulose ether, futhi izinga lokugcinwa kwamanzi le-HPMC eshintshiwe ye-gypsum slurry ene-viscosity ehlukile kancane kancane yafinyelela endaweni yokugcwala ngokwenyuka komthamo. Ukugcinwa kwamanzi e-Gypsum kuvame ukulingana ne-viscosity ye-cellulose ether, ekubukeni okuphezulu akunawo umthelela omncane.

(3) Izinto zangaphakathi ezishintsha ukugcinwa kwamanzi kwe-cellulose ether nezinga lokushisa zihlobene eduze ne-microscopic morphology ye-cellulose ether esigabeni soketshezi. Ekugxiliseni okuthile, i-cellulose ether ijwayele ukuhlangana ukuze yakhe izinhlangano ezinkulu ze-colloidal, ivimbele umzila wokuthutha amanzi wengxube ye-gypsum ukuze kuzuzwe ukugcinwa kwamanzi okuphezulu. Kodwa-ke, ngokukhuphuka kwezinga lokushisa, ngenxa yempahla ye-thermal gelation ye-cellulose ether ngokwayo, i-colloid association enkulu eyakhiwe ngaphambilini iphinde ihlakazeke kabusha, okuholela ekwehleni kokusebenza kokugcinwa kwamanzi.


Isikhathi sokuthumela: Jan-26-2023
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