Cellulose ether gyara siminti slurry

An yi nazarin tasirin tsarin tsarin kwayoyin daban-daban na ether maras ionic a kan tsarin pore na siminti slurry ta hanyar gwajin yawan aiki da macroscopic da microscopic pore tsarin kallo.Sakamakon ya nuna cewa nonionic cellulose ether zai iya ƙara porosity na ciminti slurry.Lokacin da danko na non-ion cellulose ether modified slurry yayi kama, da porosity nahydroxyethyl cellulose ether(HEC) gyara slurry ya fi na hydroxypropyl methyl cellulose ether (HPMC) da methyl cellulose ether (MC) gyara slurry.Ƙananan danko/dangi na kwayoyin halitta na HPMC cellulose ether tare da irin wannan abun ciki na rukuni, ƙarami da porosity na gyaran siminti slurry.Non-ionic cellulose ether iya rage surface tashin hankali na ruwa lokaci da kuma sanya siminti slurry sauki samar da kumfa.Non-ionic cellulose ether kwayoyin suna directionally adsorbed a gas-ruwa dubawa na kumfa, wanda kuma yana kara danko na siminti slurry lokaci da kuma kara habaka da ikon da sumunti slurry don daidaita kumfa.

Mabuɗin kalmomi:nonionic cellulose ether;Siminti slurry;Tsarin pore;Tsarin kwayoyin halitta;Tashin hankali;danko

Nonionic cellulose ether (nan gaba ake magana a kai da cellulose ether) yana da kyakkyawan kauri da riƙon ruwa, kuma ana amfani da shi sosai a busasshiyar turmi mai gauraya, siminti mai haɗa kai da sauran sabbin kayan tushen siminti.Cellulose ethers da aka yi amfani da su a cikin kayan da ke da siminti yawanci sun haɗa da methyl cellulose ether (MC), hydroxypropyl methyl cellulose ether (HPMC), hydroxyethyl methyl cellulose ether (HEMC) da kuma hydroxyethyl cellulose ether (HEC), daga cikinsu HPMC da HEMC sune aikace-aikace na yau da kullum. .

Cellulose ether na iya tasiri sosai ga tsarin pore na siminti slurry.Pourchez et al., Ta hanyar gwaji mai yawa, gwajin girman pore (hanyar allurar mercury) da kuma nazarin hoto na sEM, sun kammala cewa ether cellulose na iya ƙara adadin pores tare da diamita na kusan 500nm da pores tare da diamita na kusan 50-250μm a ciki. siminti slurry.Haka kuma, don taurare ciminti slurry, The pore size rarraba low kwayoyin nauyi HEC modified siminti slurry yayi kama da na tsantsar ciminti slurry.Jimlar pore girma na high kwayoyin nauyi HEC modified siminti slurry ne mafi girma fiye da na tsantsa siminti slurry, amma kasa fiye da na HPMC modified siminti slurry tare da wajen guda daidaito.Ta hanyar lura da SEM, Zhang et al.ya gano cewa HEMC na iya ƙara yawan pores tare da diamita na kusan 0.1mm a cikin turmi siminti.Har ila yau, sun gano ta hanyar gwajin allurar mercury cewa HEMC na iya ƙara yawan adadin pore da matsakaicin diamita na siminti slurry, wanda ya haifar da karuwa mai yawa a cikin adadin manyan pores tare da diamita na 50nm ~ 1μm da manyan pores tare da diamita na ƙari. fiye 1μm.Duk da haka, an rage yawan pores da diamita kasa da 50nm.Saric-Coric et al.An yi imani da cewa ether cellulose zai sa ciminti slurry ya fi lalacewa kuma ya haifar da karuwar macropores.Jenni et al.gwada yawan aiki kuma ya ƙaddara cewa ƙarar ƙarar ƙarar ɗigon ruwa na HEMC da aka gyara turmi siminti ya kai kusan 20%, yayin da turmi mai tsafta ya ƙunshi ƙaramin adadin iska.Silva et al.An gano cewa baya ga kololuwar biyu a 3.9 nm da 40 ~ 75nm a matsayin siminti zalla, akwai kuma kololuwa biyu a 100 ~ 500nm kuma fiye da 100μm ta hanyar gwajin allurar mercury.Ma Baoguo et al.ya gano cewa ether cellulose ya karu da adadi mai kyau tare da diamita kasa da 1μm da manyan pores tare da diamita fiye da 2μm a cikin turmi siminti ta hanyar gwajin allurar mercury.Amma ga dalilin da cewa cellulose ether ƙara porosity na ciminti slurry, yawanci yi imani da cewa cellulose ether yana da surface aiki, zai wadãtar a cikin iska da ruwa dubawa, forming wani fim, don haka kamar yadda ya tabbatar da kumfa a cikin sumunti slurry.

Ta hanyar nazarin wallafe-wallafen da ke sama, ana iya ganin cewa tasirin cellulose ether a kan tsarin pore na kayan da ke da siminti ya sami kulawa sosai.Duk da haka, akwai nau'o'in ether na cellulose da yawa, irin nau'in ether na cellulose iri ɗaya, nauyin kwayoyinsa na dangi, abun ciki na rukuni da sauran sigogin tsarin kwayoyin halitta ma sun bambanta sosai, kuma masu bincike na gida da na waje akan zaɓin ether cellulose yana iyakance ne kawai ga aikace-aikacen su. filin, rashin wakilci, ƙaddamarwa ba makawa "overgeneralization", don haka bayanin tsarin ether cellulose bai isa ba.A cikin wannan takarda, an yi nazarin tasirin ether cellulose tare da tsarin kwayoyin halitta daban-daban akan tsarin pore na siminti slurry ta hanyar gwaji mai yawa da kuma macroscopic da microscopic pore tsarin kallo.

1. Gwaji

1.1 Raw Materials

Simintin ya kasance siminti na P·O 42.5 na yau da kullun na Portland wanda Huaxin Cement Co., LTD ya kera. kuma an ƙididdige tsarin tsari ta hanyar Bogue.

Cellulose ether ya zaɓi nau'ikan ether na kasuwanci guda huɗu, bi da bi methyl cellulose ether (MC), hydroxypropyl methyl cellulose ether (HPMC1, HPMC2) da hydroxyethyl cellulose ether (HEC), tsarin kwayoyin HPMC1 da HPMC2 kama, amma danko yana da ƙasa da HPMC2. , Wato, dangi na kwayoyin halitta na HPMC1 ya fi na HPMC2.Saboda irin wannan kaddarorin na hydroxyethyl methyl cellulose ether (HEMc) da HPMC, ba a zaɓi HEMCs a cikin wannan binciken ba.Don kauce wa tasirin danshi akan sakamakon gwaji, an gasa duk ethers cellulose a 98 ℃ na 2h kafin amfani.

An gwada dankowar ether ta NDJ-1B rotary viscosimeter (Kamfanin Shanghai Changji).Matsakaicin maganin gwajin gwaji (rabo mai yawa na cellulose ether zuwa ruwa) shine 2.0%, zafin jiki shine 20 ℃, kuma yawan juyawa shine 12r / min.An gwada tashin hankalin saman ether cellulose ta hanyar zobe.Kayan gwajin shine JK99A tensiometer atomatik (Kamfanin Shanghai Zhongchen).Matsakaicin maganin gwajin shine 0.01% kuma zafin jiki shine 20 ℃.Ana samar da abun ciki na ƙungiyar ether cellulose ta masana'anta.

Dangane da danko, tashin hankali da kuma abun ciki na rukuni na cellulose ether, lokacin da maganin maida hankali shine 2.0%, rabon danko na HEC da HPMC2 shine 1: 1.6, da kuma danko rabo na HEC da MC bayani shine 1: 0.4, amma a cikin wannan gwajin, ruwa-ciminti rabo ne 0.35, matsakaicin siminti rabo ne 0.6%, da taro rabo na cellulose ether zuwa ruwa ne game da 1.7%, kasa da 2.0%, da synergistic sakamako na ciminti slurry a kan danko, don haka Danko bambanci na HEC, HPMC2 ko MC modified ciminti slurry ne kananan.

Dangane da danko, tashin hankali na sama da abun ciki na rukuni na ether cellulose, tashin hankali na kowane ether cellulose ya bambanta.Cellulose ether yana da ƙungiyoyi biyu na hydrophilic (hydroxyl da ether ƙungiyoyi) da ƙungiyoyin hydrophobic (methyl da glucose carbon zobe), wani surfactant ne.Cellulose ether ya bambanta, nau'in da abun ciki na hydrophilic da hydrophobic kungiyoyin sun bambanta, yana haifar da tashin hankali daban-daban.

1.2 Hanyoyin gwaji

An shirya nau'ikan siminti iri shida, gami da tsantsar siminti slurry, ether cellulose huɗu (MC, HPMCl, HPMC2 da HEC) slurry ɗin siminti da aka gyara tare da rabon siminti 0.60% da HPMC2 da aka gyara siminti tare da rabon siminti 0.05%.Ref, MC - 0.60, HPMCl - 0.60, Hpmc2-0.60.HEC 1-0.60 da hpMC2-0.05 suna nuna cewa rabon ciminti na ruwa shine 0.35.

Ciminti slurry farko daidai da GB/T 17671 1999 "cement turmi ƙarfi gwajin Hanyar (ISO Hanyar)" sanya a cikin 40mm × 40mm × 160mm prisms gwajin block, karkashin yanayin 20 ℃ shãfe haske curing 28d.Bayan an auna da kirga girmansa, sai aka fasa buɗaɗɗe da ƙaramin guduma, kuma an lura da yanayin rami na tsakiyar ɓangaren gwajin kuma an ɗauki hoto tare da kyamarar dijital.A lokaci guda, an ɗauki ƙananan guda na 2.5 ~ 5.0mm don kallo ta microscope na gani (HIROX microscope na bidiyo mai girma uku) da na'urar duba microscope (JSM-5610LV).

2. Sakamakon gwaji

2.1 Bayyanar yawa

Dangane da rarrabuwar siminti slurry da aka gyara ta daban-daban ethers cellulose, (1) bayyanannun yawa na tsarkakakken siminti slurry shine mafi girma, wanda shine 2044 kg/m³;A bayyane yake na nau'ikan nau'ikan selular ether na ether tare da ciminti na 0.60% ~ 88% na cirewa na cirewa wanda ya haifar da karuwa a fannin ciminti slurry.(2) Lokacin da rabo daga ciminti zuwa ciminti ne 0.60%, sakamakon daban-daban cellulose ethers a kan porosity na siminti slurry ne sosai daban-daban.A danko na HEC, HPMC2 da MC modified ciminti slurry ne kama, amma na fili yawa na HEC modified ciminti slurry ne mafi girma, yana nuna cewa porosity na HEC modified ciminti slurry ne karami fiye da na HPMc2 da Mc modified ciminti slurry tare da kama danko. .HPMc1 da HPMC2 suna da irin wannan abun cikin rukuni, amma dankowar HPMCl ya yi ƙasa da na HPMC2, kuma ƙimar da ke fitowa ta HPMCl da aka gyara ta siminti tana da girma fiye da na HPMC2 da aka gyara siminti slurry, wanda ke nuna cewa lokacin da abun cikin ƙungiyar yayi kama. , ƙananan danko na ether cellulose, ƙananan porosity na slurry ciminti da aka gyara.(3) Lokacin da siminti-zuwa-ciminti rabo ne kadan (0.05%), da fili yawa na HPMC2-gyara ciminti slurry ne m kusa da cewa na tsarki ciminti slurry, yana nuna cewa sakamakon cellulose ether a kan porosity na siminti. slurry kadan ne.

2.2 Macroscopic pore

Dangane da hotunan sashe na cellulose ether slurry wanda aka gyara ta hanyar kyamarar dijital, slurry mai tsabta yana da yawa sosai, kusan babu pores na bayyane;Nau'o'in cellulose ether guda huɗu da aka gyara slurry tare da rabon ciminti 0.60% duk suna da ƙarin pores na macroscopic, yana nuna cewa ether cellulose yana haifar da haɓakar porosity na siminti.Hakazalika da sakamakon gwajin da aka yi a bayyane, tasirin nau'in ether na cellulose daban-daban da abubuwan da ke ciki akan porosity na simintin slurry ya bambanta sosai.Dankowar HEC, HPMC2 da MC modified slurry yayi kama, amma porosity na HEC modified slurry ya fi na HPMC2 da MC modified slurry.Ko da yake HPMC1 da HPMC2 suna da irin wannan abun ciki na rukuni, HPMC1 da aka gyara slurry tare da ƙananan danko yana da ƙaramin porosity.Lokacin da siminti-zuwa-ciminti rabo na HPMc2 modified slurry ne kadan (0.05%), adadin macroscopic pores an dan kadan ya karu fiye da na tsarki siminti slurry, amma ƙwarai rage fiye da na HPMC2 modified slurry da 0.60% ciment-zuwa. -ciminti rabo.

2.3 Ƙaƙƙarfan ƙuraje

4. Kammalawa

(1) Cellulose ether na iya ƙara porosity na siminti slurry.

(2) Sakamakon cellulose ether akan porosity na ciminti slurry tare da sigogi daban-daban na tsarin kwayoyin halitta ya bambanta: lokacin da danko na cellulose ether wanda aka gyara siminti slurry yayi kama, da porosity na HEC modified ciminti slurry ne karami fiye da na HPMC da MC modified. siminti slurry;Ƙananan danko/dangi na kwayoyin halitta na HPMC cellulose ether tare da irin wannan abun ciki na rukuni, ƙananan porosity na slurry siminti da aka gyara.

(3) Bayan ƙara cellulose ether a cikin ciminti slurry, da surface tashin hankali na ruwa lokaci ne rage, sabõda haka, da ciminti slurry ne mai sauki samar da kumfa i cellulose ether kwayoyin directional adsorption a cikin kumfa gas-ruwa dubawa, inganta ƙarfi da taurin na da kumfa ruwa adsorption fim a cikin kumfa gas-ruwa dubawa, inganta ƙarfin kumfa ruwa fim da kuma karfafa ikon da m laka don daidaita kumfa.