Cov pab pawg hydroxyl nyob raucellulose ethermolecules thiab oxygen atoms ntawm ether bonds yuav tsim hydrogen bonds nrog dej molecules, tig dej dawb rau hauv cov dej khi, yog li ua lub luag haujlwm zoo hauv dej tuav; Kev sib koom ua ke ntawm cov dej molecules thiab cellulose ether molecular chains tso cai rau cov dej molecules nkag mus rau sab hauv ntawm cellulose ether macromolecular saw thiab yuav tsum muaj zog txwv, yog li tsim dej dawb thiab entangled dej, uas txhim kho cov dej tuav ntawm cement slurry; cellulose ether txhim kho cov khoom rheological, ntxeem tau network qauv thiab osmotic siab ntawm cov cement slurry tshiab los yog cov yeeb yaj kiab-forming zog ntawm cellulose ether cuam tshuam cov diffusion ntawm dej.
Cov dej tuav ntawm cellulose ether nws tus kheej los ntawm solubility thiab lub cev qhuav dej ntawm cellulose ether nws tus kheej. Lub peev xwm hydration ntawm hydroxyl pab pawg ib leeg tsis txaus them rau cov khoom siv hydrogen muaj zog thiab van der Waals rog ntawm cov molecules, yog li nws tsuas o tab sis tsis yaj hauv dej. Thaum cov khoom hloov pauv tau nkag mus rau hauv cov saw hlau molecular, tsis yog tsuas yog cov neeg hloov pauv puas tsuaj rau cov saw hlau hydrogen, tab sis kuj tseem cuam tshuam cov interchain hydrogen bonds raug rhuav tshem vim qhov sib txuas ntawm cov khoom hloov ntawm cov saw hlau uas nyob ib sab. Qhov loj dua qhov hloov pauv, qhov kev ncua deb ntawm cov molecules ntau dua, thiab qhov cuam tshuam ntau dua ntawm kev rhuav tshem hydrogen bonds. Tom qab cov cellulose lattice swells, cov tshuaj nkag mus, thiab cov cellulose ether ua dej-soluble, tsim ib tug high-viscosity tov, uas plays lub luag hauj lwm nyob rau hauv dej tuav.
Cov yam ntxwv cuam tshuam rau kev khaws cia dej:
Viscosity: Qhov ntau dua qhov viscosity ntawm cellulose ether, qhov dej tuav tau zoo dua, tab sis qhov siab dua qhov viscosity, qhov siab dua qhov hnyav ntawm cov cellulose ether, thiab nws cov solubility txo qis, uas muaj kev cuam tshuam tsis zoo rau cov concentration thiab kev tsim kho. ntawm mortar. Feem ntau hais lus, rau tib yam khoom, cov txiaj ntsig viscosity ntsuas los ntawm cov txheej txheem sib txawv yog qhov sib txawv heev, yog li thaum sib piv cov viscosity, nws yuav tsum tau nqa tawm ntawm tib txoj kev ntsuas (xws li kub, rotor, thiab lwm yam).
Ntxiv tus nqi: Qhov ntau dua ntawm cov cellulose ether ntxiv rau hauv mortar, qhov dej tuav tau zoo dua. Feem ntau, me me ntawm cellulose ether tuaj yeem txhim kho cov dej tuav tus nqi ntawm mortar. Thaum tus nqi nce mus txog ib theem, qhov sib txawv ntawm cov dej khaws cia qeeb qeeb.
Particle fineness: Qhov zoo dua cov khoom, qhov zoo dua cov dej tuav. Thaum cov khoom loj ntawm cellulose ether tuaj rau hauv kev sib cuag nrog dej, qhov chaw tam sim ntawd dissolves thiab tsim cov gel los qhwv cov khoom los tiv thaiv cov dej molecules los ntawm kev nkag mus ntxiv. Qee lub sij hawm, txawm tias lub sij hawm ntev stirring tsis tuaj yeem ua tau zoo dispersion thiab dissolution, tsim turbid flocculent tov los yog agglomeration, uas zoo heev cuam tshuam cov dej tuav ntawm cellulose ether. Solubility yog ib qho tseem ceeb ntawm kev xaiv cellulose ether. Fineness kuj yog ib qho tseem ceeb qhia txog kev ua tau zoo ntawm methyl cellulose ether. Fineness cuam tshuam rau solubility ntawm methyl cellulose ether. Coarser MC feem ntau yog granular thiab tuaj yeem yaj tau yooj yim hauv dej yam tsis muaj agglomeration, tab sis tus nqi tawg yog qeeb heev thiab nws tsis haum rau siv hauv cov tshuaj khib nyiab qhuav.
Qhov kub thiab txias: Raws li qhov kub thiab txias nce, cov dej tuav ntawm cellulose ethers feem ntau txo qis, tab sis qee qhov hloov kho cellulose ethers kuj muaj cov dej zoo khaws cia hauv qhov kub thiab txias; Thaum qhov kub nce siab, cov dej ntawm cov polymers tsis muaj zog, thiab cov dej ntawm cov chains raug tshem tawm. Thaum lub cev qhuav dej txaus, cov molecules pib sib sau los ua ib qho kev sib txuas ntawm peb sab gel.
Cov qauv molecular: Cellulose ethers nrog qis hloov pauv muaj cov dej tuav tau zoo dua.
Thickening thiab thixotropy
Thickening:
Cov txiaj ntsig ntawm kev sib txuas muaj peev xwm thiab kev ua haujlwm los tiv thaiv sagging: Cellulose ethers muab cov tshuaj khib nyiab zoo heev viscosity, uas tuaj yeem ua rau muaj peev xwm ua kom muaj peev xwm ntawm cov mortar ntub nrog cov txheej txheej thiab txhim kho kev ua haujlwm ntawm cov tshuaj khib nyiab. Nws yog dav siv nyob rau hauv plastering mortar, pobzeb bonding mortar thiab sab nrauv phab ntsa rwb thaiv tsev system 3.
Cov nyhuv ntawm cov khoom sib xws: Cov nyhuv thickening ntawm cellulose ethers kuj tuaj yeem ua rau muaj peev xwm tiv thaiv kev tawg thiab qhov sib xyaw ntawm cov khoom sib xyaw tshiab, tiv thaiv cov khoom siv stratification, sib cais thiab dej seepage, thiab tuaj yeem siv rau hauv fiber ntau pob zeb, underwater pob zeb thiab nws tus kheej-compacting pob zeb. .
Qhov chaw thiab cuam tshuam ntawm cov nyhuv thickening: Cov nyhuv thickening ntawm cellulose ether ntawm cov ntaub ntawv cement los ntawm cov viscosity ntawm cellulose ether kua. Nyob rau tib lub sijhawm, qhov siab dua qhov viscosity ntawm cellulose ether, qhov zoo dua qhov viscosity ntawm cov ntaub ntawv hloov cement-based, tab sis yog tias cov viscosity siab dhau lawm, nws yuav cuam tshuam rau cov dej ntws thiab kev ua haujlwm ntawm cov khoom siv (xws li lo rau lub plastering riam. ). Self-leveling mortar thiab nws tus kheej-compacting pob zeb nrog lub siab fluidity yuav tsum tau tsawg viscosity ntawm cellulose ether. Tsis tas li ntawd, cov nyhuv thickening ntawm cellulose ether tseem yuav ua rau kom cov dej xav tau ntawm cov ntaub ntawv cement-based thiab ua rau cov khoom siv khib nyiab.
Thixotropy:
High-viscosity cellulose ether aqueous tov muaj thixotropy siab, uas kuj yog ib qho tseem ceeb ntawm cellulose ether. Cov tshuaj aqueous ntawm methyl cellulose feem ntau muaj pseudoplasticity thiab tsis-thixotropic fluidity hauv qab nws cov gel kub, tab sis nthuav tawm Newtonian ndlwg zog ntawm tus nqi qis. Pseudoplasticity nce nrog qhov nce ntawm cellulose ether molecular hnyav lossis concentration, thiab tsis muaj dab tsi cuam tshuam nrog hom kev hloov pauv thiab qib kev hloov pauv. Yog li, cellulose ethers ntawm tib qib viscosity, txawm tias MC, HPMC, lossis HEMC, ib txwm qhia tib lub zog rheological ntev npaum li qhov concentration thiab kub nyob twj ywm. Thaum qhov kub thiab txias nce, cov txheej txheem gel yog tsim, thiab muaj thixotropic txaus tshwm sim. Cellulose ethers nrog siab concentration thiab qis viscosity qhia thixotropy txawm tias qis dua qhov kub ntawm gel. Cov cuab yeej no muaj txiaj ntsig zoo rau kev kho cov qib thiab sagging ntawm lub tsev mortar thaum tsim kho.
Huab cua nkag
Lub hauv paus ntsiab lus thiab cov txiaj ntsig ntawm kev ua haujlwm: Cellulose ether muaj qhov cuam tshuam rau huab cua tseem ceeb ntawm cov khoom siv cement-based tshiab. Cellulose ether muaj ob pawg hydrophilic (hydroxyl pawg, ether pawg) thiab pawg hydrophobic (methyl pawg, qab zib rings). Nws yog ib qho surfactant nrog kev ua haujlwm saum npoo, yog li muaj cov nyhuv cua nkag. Cov nyhuv ntawm huab cua nkag yuav ua rau cov nyhuv pob, uas tuaj yeem txhim kho kev ua haujlwm ntawm cov khoom sib xyaw tshiab, xws li ua kom cov yas thiab smoothness ntawm mortar thaum ua haujlwm, uas muaj txiaj ntsig zoo rau kev sib kis ntawm mortar; nws tseem yuav ua rau kom cov khoom siv khib nyiab thiab txo cov nqi ntawm cov tshuaj khib nyiab.
Kev cuam tshuam rau cov khoom siv kho tshuab: Cov cua nkag mus rau hauv huab cua yuav ua rau cov porosity ntawm cov khoom tawv tawv thiab txo nws cov khoom siv xws li lub zog thiab elastic modulus.
Cov nyhuv ntawm fluidity: Raws li cov surfactant, cellulose ether kuj muaj qhov ntub dej los yog lubricating ntawm cov cement hais, uas ua ke nrog nws cov huab cua entraining nyhuv tsub kom lub fluidity ntawm cement-based cov ntaub ntawv, tab sis nws cov nyhuv thickening yuav txo cov fluidity. Cov nyhuv ntawm cellulose ether ntawm fluidity ntawm cov ntaub ntawv cement-based yog kev sib xyaw ntawm plasticizing thiab thickening teebmeem. Feem ntau hais lus, thaum cov cellulose ether ntau npaum li cas tsawg, nws feem ntau tshwm sim raws li plasticizing lossis dej txo cov teebmeem; Thaum noj ntau npaum li cas, cov nyhuv thickening ntawm cellulose ether nce sai, thiab nws cov huab cua nkag mus rau hauv cov nyhuv yuav saturated, yog li nws manifests li thickening los yog nce dej thov.
Post lub sij hawm: Dec-23-2024