Cellulose ether
Cellulose ether yog ib lo lus dav dav rau cov khoom tsim los ntawm cov tshuaj tiv thaiv ntawm alkali cellulose thiab etherifying agent nyob rau hauv qee qhov xwm txheej. Alkali cellulose raug hloov los ntawm cov neeg sawv cev etherifying sib txawv kom tau txais cov cellulose ethers sib txawv. Raws li cov khoom ionization ntawm cov substituents, cellulose ethers tuaj yeem muab faib ua ob pawg: ionic (xws li carboxymethyl cellulose) thiab non-ionic (xws li methyl cellulose). Raws li hom substituent, cellulose ether tuaj yeem muab faib ua monoether (xws li methyl cellulose) thiab sib xyaw ether (xws li hydroxypropyl methyl cellulose). Raws li kev yaj sib txawv, nws tuaj yeem muab faib ua dej-soluble (xws li hydroxyethyl cellulose) thiab organic solvent-soluble (xws li ethyl cellulose), thiab lwm yam. Cov mortar qhuav-mixed yog feem ntau dej-soluble cellulose, thiab dej-soluble cellulose yog muab faib ua hom instant thiab nto kho qeeb hom yaj.
Lub mechanism ntawm kev ua haujlwm ntawm cellulose ether hauv mortar yog raws li nram no:
(1) Tom qab cov cellulose ether hauv cov mortar yaj rau hauv dej, qhov kev faib tawm zoo thiab sib xws ntawm cov khoom siv cementitious hauv lub kaw lus tau ua kom ntseeg tau vim yog qhov kev ua haujlwm ntawm qhov chaw, thiab cov cellulose ether, ua ib qho kev tiv thaiv colloid, "qhwv" cov khoom khov kho thiab Ib txheej ntawm cov zaj duab xis lubricating tau tsim rau ntawm nws qhov chaw sab nraud, uas ua rau lub kaw lus mortar ruaj khov dua, thiab tseem txhim kho qhov fluidity ntawm cov mortar thaum lub sijhawm sib tov thiab qhov du ntawm kev tsim kho.
(2) Vim nws cov qauv molecular, cov kua cellulose ether ua rau cov dej hauv cov mortar tsis yooj yim poob, thiab maj mam tso nws tawm mus ntev, ua rau cov mortar khaws dej zoo thiab ua haujlwm tau zoo.
1. Methylcellulose (MC)
Tom qab cov paj rwb ua kom zoo lawm raug kho nrog alkali, cellulose ether raug tsim los ntawm ntau qhov kev sib xyaw nrog methane chloride ua tus neeg sawv cev etherification. Feem ntau, qib kev hloov pauv yog 1.6 ~ 2.0, thiab qhov solubility kuj txawv nrog ntau qib kev hloov pauv. Nws yog rau cov cellulose ether uas tsis yog ionic.
(1) Methylcellulose yaj tau hauv dej txias, thiab nws yuav nyuaj rau yaj hauv dej kub. Nws cov kua dej ruaj khov heev hauv pH = 3 ~ 12. Nws muaj kev sib raug zoo nrog cov hmoov txhuv nplej siab, cov roj hmab guar, thiab lwm yam thiab ntau yam surfactants. Thaum qhov kub ncav cuag qhov kub gelation, gelation tshwm sim.
(2) Qhov khaws dej ntawm methyl cellulose nyob ntawm nws qhov ntxiv ntau npaum li cas, viscosity, qhov zoo ntawm cov khoom me me thiab qhov nrawm ntawm kev yaj. Feem ntau, yog tias qhov ntxiv ntau npaum li cas, qhov zoo me me, thiab qhov viscosity loj, qhov nrawm ntawm kev khaws dej siab. Ntawm lawv, qhov nrawm ntawm kev ntxiv muaj qhov cuam tshuam loj tshaj plaws rau qhov nrawm ntawm kev khaws dej, thiab qib ntawm viscosity tsis ncaj qha rau qib ntawm kev khaws dej. Qhov nrawm ntawm kev yaj feem ntau nyob ntawm qib ntawm kev hloov pauv ntawm qhov chaw ntawm cov khoom me me cellulose thiab qhov zoo ntawm cov khoom me me. Ntawm cov cellulose ethers saum toj no, methyl cellulose thiab hydroxypropyl methyl cellulose muaj qhov nrawm ntawm kev khaws dej siab dua.
(3) Kev hloov pauv ntawm qhov kub thiab txias yuav cuam tshuam loj heev rau qhov ceev ntawm cov methyl cellulose uas khaws dej. Feem ntau, qhov kub siab dua, qhov kev khaws dej yuav phem dua. Yog tias qhov kub ntawm cov mortar tshaj 40 ° C, qhov kev khaws dej ntawm methyl cellulose yuav raug txo qis, cuam tshuam loj heev rau kev tsim cov mortar.
(4) Methyl cellulose muaj feem cuam tshuam loj rau kev tsim kho thiab kev nplaum ntawm cov mortar. Qhov "kev nplaum" ntawm no yog hais txog lub zog nplaum uas hnov ntawm tus neeg ua haujlwm lub cuab yeej thov thiab phab ntsa substrate, uas yog, qhov kev tiv thaiv shear ntawm cov mortar. Qhov kev nplaum yog siab, qhov kev tiv thaiv shear ntawm cov mortar yog loj, thiab lub zog uas cov neeg ua haujlwm xav tau hauv cov txheej txheem ntawm kev siv kuj loj, thiab kev ua haujlwm ntawm cov mortar tsis zoo. Methyl cellulose adhesion yog nyob rau theem nruab nrab hauv cov khoom cellulose ether.
2. Hydroxypropylmethylcellulose (HPMC)
Hydroxypropyl methylcellulose yog ib hom cellulose uas nws cov zis thiab kev siv tau nce sai heev nyob rau xyoo tas los no. Nws yog ib qho cellulose sib xyaw ether uas tsis yog ionic ua los ntawm paj rwb zoo tom qab alkalization, siv propylene oxide thiab methyl chloride ua tus neeg sawv cev etherification, los ntawm ntau yam kev tshuaj tiv thaiv. Qib ntawm kev hloov pauv feem ntau yog 1.2 ~ 2.0. Nws cov khoom sib txawv vim yog qhov sib txawv ntawm cov ntsiab lus methoxyl thiab cov ntsiab lus hydroxypropyl.
(1) Hydroxypropyl methylcellulose yooj yim yaj hauv dej txias, thiab nws yuav ntsib teeb meem hauv kev yaj hauv dej kub. Tab sis nws qhov kub gelation hauv dej kub yog siab dua li ntawm methyl cellulose. Qhov solubility hauv dej txias kuj zoo dua piv rau methyl cellulose.
(2) Qhov viscosity ntawm hydroxypropyl methylcellulose muaj feem cuam tshuam nrog nws qhov hnyav molecular, thiab qhov loj dua qhov hnyav molecular, qhov siab dua qhov viscosity. Kub kuj cuam tshuam rau nws qhov viscosity, thaum kub nce, viscosity txo qis. Txawm li cas los xij, nws qhov viscosity siab muaj qhov kub qis dua li methyl cellulose. Nws cov kua ruaj khov thaum khaws cia rau hauv chav sov.
(3) Qhov khaws cia dej ntawm hydroxypropyl methylcellulose nyob ntawm nws qhov ntxiv, viscosity, thiab lwm yam, thiab nws qhov khaws cia dej nyob rau hauv tib qhov ntxiv yog siab dua li ntawm methyl cellulose.
(4) Hydroxypropyl methylcellulose ruaj khov rau cov kua qaub thiab alkali, thiab nws cov kua dej ruaj khov heev hauv pH = 2 ~ 12. Caustic soda thiab dej txiv qaub tsis muaj feem cuam tshuam rau nws cov kev ua tau zoo, tab sis alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity nce ntxiv. Hydroxypropyl methylcellulose ruaj khov rau cov ntsev feem ntau, tab sis thaum qhov concentration ntawm cov ntsev ntau, qhov viscosity ntawm hydroxypropyl methylcellulose kua feem ntau nce ntxiv.
(5) Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog cov polymer sib xyaw uas yaj tau hauv dej los ua cov kua nplaum uas sib xws thiab viscosity siab dua. Xws li polyvinyl cawv, hmoov txhuv nplej siab ether, cov roj zaub, thiab lwm yam.
(6) Hydroxypropyl methylcellulose muaj kev tiv thaiv enzyme zoo dua li methylcellulose, thiab nws cov kua tsis tshua muaj peev xwm raug rhuav tshem los ntawm cov enzymes dua li methylcellulose.
(7) Qhov nplaum ntawm hydroxypropyl methylcellulose rau kev tsim kho mortar siab dua li ntawm methylcellulose.
3. Hydroxyethyl cellulose (HEC)
Nws yog ua los ntawm paj rwb zoo kho nrog alkali, thiab reacted nrog ethylene oxide ua tus neeg sawv cev etherification nyob rau hauv lub xub ntiag ntawm acetone. Qib ntawm kev hloov pauv feem ntau yog 1.5 ~ 2.0. Muaj hydrophilicity muaj zog thiab yooj yim rau nqus dej noo.
(1) Hydroxyethyl cellulose yaj tau hauv dej txias, tab sis nws nyuaj rau yaj hauv dej kub. Nws cov tshuaj ruaj khov ntawm qhov kub siab tsis muaj gelling. Nws tuaj yeem siv tau ntev hauv qhov kub siab hauv mortar, tab sis nws cov dej khaws cia qis dua li ntawm methyl cellulose.
(2) Hydroxyethyl cellulose ruaj khov rau cov kua qaub thiab alkali. Alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity me ntsis. Nws cov dispersibility hauv dej yog qhov phem dua li ntawm methyl cellulose thiab hydroxypropyl methyl cellulose.
(3) Hydroxyethyl cellulose muaj kev ua tau zoo tiv thaiv kev qaug zog rau cov mortar, tab sis nws muaj lub sijhawm ntev dua rau cov cement.
(4) Kev ua tau zoo ntawm hydroxyethyl cellulose uas tsim los ntawm qee lub tuam txhab hauv tsev yog qhov qis dua li ntawm methyl cellulose vim nws cov dej ntau thiab cov tshauv ntau.
4. Carboxymethyl cellulose (CMC)
Ionic cellulose ether yog ua los ntawm cov fiber ntuj (paj rwb, thiab lwm yam) tom qab kev kho alkali, siv sodium monochloroacetate ua tus neeg sawv cev etherification, thiab dhau los ntawm ntau yam kev kho mob tshuaj tiv thaiv. Qib ntawm kev hloov pauv feem ntau yog 0.4 ~ 1.4, thiab nws cov kev ua tau zoo cuam tshuam loj heev los ntawm qib ntawm kev hloov pauv.
(1) Carboxymethyl cellulose muaj hygroscopic ntau dua, thiab nws yuav muaj dej ntau dua thaum khaws cia rau hauv qab cov xwm txheej dav dav.
(2) Cov kua dej Carboxymethyl cellulose yuav tsis tsim cov gel, thiab qhov viscosity yuav txo qis nrog qhov nce ntawm qhov kub. Thaum qhov kub tshaj 50 ° C, qhov viscosity tsis rov qab tau.
(3) Nws qhov ruaj khov raug cuam tshuam los ntawm pH. Feem ntau, nws tuaj yeem siv rau hauv gypsum-based mortar, tab sis tsis yog hauv cement-based mortar. Thaum alkaline heev, nws poob viscosity.
(4) Nws cov dej khaws cia qis dua li ntawm methyl cellulose. Nws muaj cov nyhuv qeeb rau gypsum-based mortar thiab txo nws lub zog. Txawm li cas los xij, tus nqi ntawm carboxymethyl cellulose qis dua li ntawm methyl cellulose.
Cov hmoov roj hmab polymer uas yaj tau dua tshiab
Cov hmoov roj hmab uas tawg tau dua yog ua los ntawm kev txau kom qhuav cov polymer emulsion tshwj xeeb. Thaum ua tiav, cov colloid tiv thaiv, cov neeg sawv cev tiv thaiv kev sib sau ua ke, thiab lwm yam yuav dhau los ua cov khoom ntxiv tseem ceeb. Cov hmoov roj hmab qhuav yog qee cov khoom me me uas muaj li ntawm 80 ~ 100 hli sib sau ua ke. Cov khoom me me no yaj tau hauv dej thiab tsim cov khoom tawg ruaj khov me ntsis loj dua li cov khoom me me emulsion qub. Cov khoom tawg no yuav tsim ib zaj duab xis tom qab ziab thiab ziab. Zaj duab xis no tsis hloov pauv tau zoo li cov zaj duab xis emulsion feem ntau, thiab yuav tsis tawg dua thaum nws ntsib dej. Cov khoom tawg.
Cov roj hmab hmoov uas tawg tau dua tuaj yeem muab faib ua: styrene-butadiene copolymer, tertiary carbonic acid ethylene copolymer, ethylene-acetate acetic acid copolymer, thiab lwm yam, thiab raws li qhov no, silicone, vinyl laurate, thiab lwm yam raug grafted los txhim kho kev ua tau zoo. Cov kev ntsuas hloov kho sib txawv ua rau cov roj hmab hmoov uas tawg tau dua muaj cov yam ntxwv sib txawv xws li kev tiv thaiv dej, kev tiv thaiv alkali, kev tiv thaiv huab cua thiab kev ywj pheej. Muaj vinyl laurate thiab silicone, uas tuaj yeem ua rau cov roj hmab hmoov muaj hydrophobicity zoo. Cov vinyl tertiary carbonate uas muaj ceg ntoo siab nrog tus nqi Tg qis thiab kev ywj pheej zoo.
Thaum cov hmoov roj hmab no siv rau ntawm cov pob zeb mortar, lawv txhua tus muaj qhov cuam tshuam rau lub sijhawm teeb tsa ntawm cov cement, tab sis qhov cuam tshuam qeeb dua li ntawm kev siv ncaj qha ntawm cov emulsions zoo sib xws. Piv txwv li, styrene-butadiene muaj qhov cuam tshuam loj tshaj plaws, thiab ethylene-vinyl acetate muaj qhov cuam tshuam me tshaj plaws. Yog tias cov tshuaj tsawg dhau, qhov cuam tshuam ntawm kev txhim kho kev ua tau zoo ntawm cov pob zeb mortar tsis pom tseeb.
Cov xov polypropylene
Polypropylene fiber yog ua los ntawm polypropylene ua raw khoom thiab muaj cov khoom hloov kho kom haum. Lub fiber txoj kab uas hla feem ntau yog li 40 microns, lub zog tensile yog 300 ~ 400mpa, lub elastic modulus yog ≥3500mpa, thiab qhov kawg elongation yog 15 ~ 18%. Nws cov yam ntxwv ua tau zoo:
(1) Cov polypropylene fibers tau faib ua peb ntu hauv cov lus qhia random hauv lub mortar, tsim cov txheej txheem txhawb nqa network. Yog tias ntxiv 1 kg ntawm polypropylene fiber rau txhua tuj ntawm mortar, ntau dua 30 lab monofilament fibers tuaj yeem tau txais.
(2) Ntxiv polypropylene fiber rau hauv cov mortar tuaj yeem txo qhov tawg ntawm cov mortar hauv lub xeev yas. Txawm hais tias cov kab nrib pleb no pom lossis tsis pom. Thiab nws tuaj yeem txo qhov dej ntws thiab kev sib sau ua ke ntawm cov mortar tshiab.
(3) Rau lub cev mortar hardened, polypropylene fiber tuaj yeem txo qhov ntau ntawm cov kab nrib pleb deformation. Ntawd yog, thaum lub cev mortar hardening tsim kev ntxhov siab vim yog deformation, nws tuaj yeem tiv taus thiab kis kev ntxhov siab. Thaum lub cev mortar hardening tawg, nws tuaj yeem passivate qhov kev ntxhov siab concentration ntawm qhov kawg ntawm qhov tawg thiab txwv tsis pub qhov tawg nthuav dav.
(4) Kev sib kis zoo ntawm cov polypropylene fibers hauv kev tsim cov mortar yuav dhau los ua teeb meem nyuaj. Cov khoom siv sib tov, hom fiber thiab koob tshuaj, qhov sib piv ntawm mortar thiab nws cov txheej txheem yuav dhau los ua cov yam tseem ceeb uas cuam tshuam rau kev sib kis.
tus neeg sawv cev rau kev cob qhia huab cua
Tus neeg sawv cev rau cua nkag yog ib hom surfactant uas tuaj yeem tsim cov npuas cua ruaj khov hauv cov pob zeb tshiab lossis mortar los ntawm cov txheej txheem lub cev. Feem ntau suav nrog: rosin thiab nws cov polymers thermal, non-ionic surfactants, alkylbenzene sulfonates, lignosulfonates, carboxylic acids thiab lawv cov ntsev, thiab lwm yam.
Cov tshuaj uas ua rau huab cua nkag feem ntau siv los npaj cov plastering mortars thiab masonry mortars. Vim yog ntxiv cov tshuaj uas ua rau huab cua nkag, qee qhov kev hloov pauv hauv kev ua haujlwm ntawm cov mortar yuav raug coj los.
(1) Vim yog qhov kev qhia txog cov pa npuas, qhov yooj yim thiab kev tsim kho ntawm cov mortar sib xyaw tshiab tuaj yeem nce ntxiv, thiab kev los ntshav tuaj yeem txo qis.
(2) Tsuas yog siv cov tshuaj uas ua rau huab cua nkag mus rau hauv pwm yuav txo qhov muaj zog thiab elasticity ntawm cov pwm hauv cov mortar. Yog tias cov tshuaj uas ua rau huab cua nkag mus rau hauv pwm thiab cov tshuaj uas ua rau dej txo qis siv ua ke, thiab qhov sib piv yog qhov tsim nyog, qhov muaj zog yuav tsis txo qis.
(3) Nws tuaj yeem txhim kho qhov kev tiv thaiv te ntawm cov mortar tawv, txhim kho qhov tsis nkag ntawm cov mortar, thiab txhim kho qhov kev tiv thaiv kev yaig ntawm cov mortar tawv.
(4) Tus neeg sawv cev uas muaj cua nkag yuav ua rau cov pa ntawm cov mortar nce ntxiv, uas yuav ua rau cov mortar ntsws ntau ntxiv, thiab tus nqi ntsws tuaj yeem txo qis los ntawm kev ntxiv tus neeg sawv cev txo dej.
Vim tias cov tshuaj uas ua rau huab cua nkag tau ntxiv me me heev, feem ntau tsuas yog ob peb feem kaum txhiab ntawm tag nrho cov khoom siv cementitious, yuav tsum tau xyuas kom meej tias nws tau ntsuas thiab sib xyaw kom raug thaum lub sijhawm tsim cov mortar; cov yam xws li cov txheej txheem sib tov thiab lub sijhawm sib tov yuav cuam tshuam loj heev rau qhov ntau ntawm cov pa nkag. Yog li ntawd, nyob rau hauv cov xwm txheej tam sim no hauv tsev thiab kev tsim kho, kev ntxiv cov tshuaj uas ua rau huab cua nkag rau hauv cov mortar yuav tsum tau ua ntau yam kev sim.
tus neeg sawv cev rau lub zog thaum ntxov
Siv los txhim kho lub zog thaum ntxov ntawm cov pob zeb thiab cov mortar, cov tshuaj sulfate thaum ntxov siv feem ntau, feem ntau suav nrog sodium sulfate, sodium thiosulfate, aluminium sulfate thiab potassium aluminium sulfate.
Feem ntau, anhydrous sodium sulfate yog siv dav, thiab nws cov koob tshuaj tsawg thiab cov nyhuv ntawm lub zog thaum ntxov yog qhov zoo, tab sis yog tias cov koob tshuaj loj dhau, nws yuav ua rau nthuav dav thiab tawg hauv theem tom qab, thiab tib lub sijhawm, alkali rov qab yuav tshwm sim, uas yuav cuam tshuam rau qhov tsos thiab cov nyhuv ntawm cov txheej kho kom zoo nkauj nto.
Calcium formate kuj yog ib qho tshuaj tiv thaiv kev khov zoo. Nws muaj cov nyhuv zoo thaum ntxov, tsawg dua cov kev phiv, sib haum xeeb zoo nrog lwm cov admixtures, thiab ntau yam khoom zoo dua li cov tshuaj sulfate thaum ntxov, tab sis tus nqi siab dua.
tshuaj tiv thaiv kev khov
Yog tias cov mortar siv rau qhov kub tsis zoo, yog tias tsis muaj kev ntsuas tiv thaiv kev khov, kev puas tsuaj los ntawm te yuav tshwm sim thiab lub zog ntawm lub cev tawv yuav raug rhuav tshem. Antifreeze tiv thaiv kev puas tsuaj los ntawm kev khov los ntawm ob txoj hauv kev los tiv thaiv kev khov thiab txhim kho lub zog thaum ntxov ntawm mortar.
Ntawm cov tshuaj antifreeze uas siv ntau, calcium nitrite thiab sodium nitrite muaj cov teebmeem antifreeze zoo tshaj plaws. Vim tias calcium nitrite tsis muaj potassium thiab sodium ions, nws tuaj yeem txo qhov tshwm sim ntawm alkali aggregate thaum siv rau hauv cov pob zeb ua vaj tse, tab sis nws txoj haujlwm tsis zoo me ntsis thaum siv rau hauv mortar, thaum sodium nitrite muaj kev ua haujlwm zoo dua. Antifreeze yog siv ua ke nrog tus neeg sawv cev lub zog thaum ntxov thiab cov dej txo kom tau txais cov txiaj ntsig zoo. Thaum cov mortar qhuav sib xyaw nrog antifreeze siv ntawm qhov kub tsis qis heev, qhov kub ntawm qhov sib tov yuav tsum tau nce kom haum, xws li sib tov nrog dej sov.
Yog tias qhov ntau ntawm cov tshuaj tiv thaiv kev khov ntau dhau, nws yuav txo qhov zog ntawm cov tshuaj khib nyiab hauv theem tom qab, thiab qhov chaw ntawm cov tshuaj khib nyiab tawv yuav muaj teeb meem xws li alkali rov qab, uas yuav cuam tshuam rau qhov tsos thiab cov nyhuv ntawm cov txheej kho kom zoo nkauj saum npoo.
Lub sijhawm tshaj tawm: Lub Ib Hlis-16-2023