Dab tsi yog Qhov Mechanism Ntawm Naphthalene Superplasticizer?

Adsorption ntawm naphthalene-based high-performance dej-txo tus neeg saib xyuas ntawm cov cement hais thiab nws cov nyhuv dispersing ntawm cov ntaub ntawv cementitious.Thaum cov dej ntxiv rau cov cement thiab sib tov los ua cov cement slurry, nws nthuav tawm cov qauv flocculated ntawm qib microscopic. Thaum ntxov ntawm hydration, ntau yam cement hydration khoom pib tsim. Cov zaub mov tseem ceeb hauv cov cement nqa cov nqi sib txawv thaum lub sij hawm hydration txheej txheem, ua rau kev sib nrig sib nyiam. Nyob rau hauv lub flocculated qauv, ib tug ntau npaum li cas ntawm cov dej yog daig. Thaum cov dej-txo tus neeg sawv cev molecules adsorb rau hauv cov cement hais hauv slurry, lawv tsim ib txheej hluav taws xob ob npaug rau ntawm qhov chaw, dhau los ua ib tus neeg polar molecules lossis molecular pawg. Qhov kawg hydrophobic adsorbs mus rau saum npoo ntawm cov cement hais, thaum lub hydrophilic kawg ntsib cov dej aqueous, tsim ib zaj duab xis monomolecular lossis multimolecular adsorption. Cov nyhuv no nyiam cov dej molecules thiab cais cov flocculated cement particles, muab tso rau hauv lub xeev dispersed heev thiab tso cov dej daig hauv flocs. Ntxiv mus, cov kev taw qhia adsorption ntawm cov surfactant ua rau sab nrauv ntawm cov cement hais kom nqa zoo li cov nqi, tsim kev sib nrig sib repulsion, thaum kawg ua rau cov cement slurry tsim kev ncua tsis ruaj khov.

Lubrication ntawm cement particles nto.Lub ncov qaum teb hydrophilic kawg ntawm naphthalene-raws li kev ua haujlwm siab dej-txo tus neeg saib xyuas cov tshuaj aqueous thiab tsim hydrogen bonds nrog dej molecules. Tsis tas li ntawd, hydrogen kev sib txuas ntawm cov dej molecules tsim cov yeeb yaj kiab dej ntawm cov cement micro-particles, tiv thaiv kev sib cuag ncaj qha ntawm cov cement hais thiab muab lubrication zoo. Cov npuas me me hauv cov cement slurry zoo ib yam li qhwv los ntawm cov pab pawg adsorptive ntawm cov neeg ua haujlwm siab dej-txo cov neeg ua haujlwm, ua rau cov npuas ua rau ib leeg, nrog rau kev tshem tawm cov cement particles vim nqa cov nqi, ua haujlwm zoo li yog muaj ntau lub pob bearings ntawm cov cement hais.

2. Cov ntaub ntawv tseem ceeb thiab cov kev xav tau zoo siv hauv kev tsim khoom

1.Industrial naphthalene
Cov mis mos molecular ntawm naphthalene yog C10H8, nrog rau qhov hnyav molecular ntawm 128. Cov kev ua haujlwm ntau lawm tau pom tias cov khoom siv raw nrog cov ntsiab lus siab ntawm cov naphthalene ua rau muaj kev ua tau zoo ntawm cov naphthalene-raws li kev ua haujlwm siab dej-txo tus neeg saib xyuas, nrog cov ntsiab lus ntawm cov cua hauv qab. . Feem ntau cov naphthalene-raws li kev ua tau zoo ntawm cov dej-txo cov neeg ua haujlwm hauv Suav teb siv cov naphthalene ua cov khoom siv raw, thaum cov naphthalene refined tsis tshua muaj siv. Naphthalene yog muab rho tawm los ntawm thee tar distillation; khoom muaj naphthalene yog dawb, cia rau me ntsis liab los yog daj crystalline flakes los yog hmoov. Cov kua dej muaj naphthalene tsis muaj xim tshwj xeeb. Muaj naphthalene melts ntawm 80 degree thiab boils ntawm 218 degree. Nws yog insoluble nyob rau hauv dej tab sis yooj yim sublimates, nrog ib tug txawv tsw. Kev lag luam naphthalene tau muab faib ua cov khoom lag luam qib thib ib thiab qib thib ob, thiab nws cov kev qhia tshwj xeeb yuav tsum ua kom tau raws li cov kev xav tau teev tseg hauv Table 3-4.

2.Sulfuric acid
Sulfuric acid yog ib qho ntawm cov khoom siv tseem ceeb rau kev tsim cov naphthalene-raws li cov dej-txo cov neeg ua haujlwm siab. Feem ntau, sulfuric acid uas muaj ntau dua 98% yog siv. Nws yog xim tsis muaj xim lossis lub teeb daj pob tshab uas muaj qhov ntom ntom ntawm 1.84 g / cm³, cov qauv molecular ntawm H2SO4, thiab qhov hnyav molecular ntawm 98. Concentrated sulfuric acid tau muab faib ua qib siab tshaj, qib thawj, thiab qib tsim nyog, thiab nws cov kev ua tau zoo. cov ntsuas yuav tsum ua tau raws li cov lus qhia tshwj xeeb tau teev tseg hauv Table 3-5.

3.Industrial formaldehyde tov
Cov concentration ntawm kev lag luam formaldehyde tov yog 35% mus rau 37%. Nws yog cov kua tsis muaj xim, pob tshab nrog cov ntxhiab tsw thiab qhov ntom ntawm 1.10 g / cm³ ntawm 15 degree, nrog cov mis molecular ntawm CH2O thiab molecular hnyav ntawm 30. Formaldehyde muab faib ua qib siab tshaj, qib thawj, thiab qib tsim nyog, thiab nws cov ntsuas kev ua tau zoo yuav tsum ua tau raws li cov lus qhia tshwj xeeb tau teev tseg hauv Table 3-6.

4. Sodium hydroxide
Sodium hydroxide rau kev lag luam siv los ntawm ob qho tib si kua thiab khoom. Cov khoom lag luam yuav tsum tau npaj rau hauv ib qho kev daws teeb meem nrog 30% mus rau 40% ua ntej siv. Cov ntsuas kev ua tau zoo ntawm cov khoom siv sodium hydroxide yuav tsum ua kom tau raws li qhov yuav tsum tau teev tseg hauv Table 3-7. Los ntawm Table 3-7, nws tuaj yeem pom tias cov ntsiab lus sodium chloride sib txawv heev nyob ntawm txoj kev tsim khoom. Sodium hydroxide tsim los ntawm txoj kev mercury muaj cov ntsiab lus sodium chloride qis tshaj plaws, thaum uas tsim los ntawm txoj kev diaphragm muaj qhov siab tshaj plaws.