Txoj Kev Txhim Kho Ntawm Polycarboxylate Superplasticizers

Txoj kev loj hlob ntawm polycarboxylate superplasticizers

1. Tom qab superplasticizer, raws li lub npe qhia, yog ib qho kev sib xyaw ua ke uas tuaj yeem txo cov dej haus ntawm kev sib xyaw thaum tswj cov pob zeb zoo tib yam. Lub ntiaj teb thawj zaug siv superplasticizer yog sodium lignosulfonate, uas tau muab rho tawm los ntawm cov kua txiv hmab txiv ntoo pov tseg thaum ntxov 30s ntawm lub xyoo pua 20th, tab sis cov dej txo qis.

Tom qab ntawd, Dr. Kenichi Hattori ntawm Nyij Pooj thawj zaug siv cov formaldehyde condensate ntawm naphthalene sulfonate ua cov pob zeb tawg, thiab tom qab ntawd cov melamine sulfonate formaldehyde condensate thiab lwm cov pob zeb superplasticizers ntawm sulfonate thiab formaldehyde condensate tshwm sim. Piv nrog rau thawj tiam ntawm superplasticizers, cov dej txo tus nqi yog zoo heev, tab sis cov slump tuav nyhuv yog tsis zoo, thiab cov txheej txheem ntawm cov khoom yog tsis ruaj tsis khov.

Thaum ntxov 80s, tiam tshiab ntawm superplasticizers - polycarboxylic acid superplasticizers kuj tau tsim los ntawm Nyiv. Piv nrog rau ob tiam dhau los ntawm superplasticizers, polycarboxylic acid superplasticizers muaj tsawg npaum li cas, txo cov dej siab, txo qis me me thaum lub sij hawm, thiab muaj txiaj ntsig zoo. Nyob rau tib lub sijhawm, nws muaj ntau yam zoo xws li kev tiv thaiv ib puag ncig ntsuab thiab cov khoom lag luam zoo, thiab tam sim no yog lub ntiaj teb kev txiav-ntug tshaj plaws, cov ntsiab lus siv thev naus laus zis siab tshaj plaws, cov ntawv thov zoo tshaj plaws, thiab kev ua tiav zoo tshaj plaws ntawm cov pob zeb superplasticizer.

2. Mechanism ntawm kev txiav txim ntawm polycarboxylate superplasticizer 1

Los ntawm qhov kev xav ntawm cov qauv molecular, polycarboxylic acid superplasticizer yog hom zuag, nrog ntau pab pawg ua haujlwm ntawm cov saw tseem ceeb, muaj zog polarity, thiab hydrophilic polyether ntu nyob rau hauv cov saw hlau sab, uas cov ntu polyether nrog hydrophilicity yog ntev dua thiab muaj ntau dua. , thaum cov molecular ntu nrog hydrophobicity luv dua thiab tus lej tsawg dua. Cov qauv txuas polyethylene (tseem hu ua graft saw) ntawm cov saw hlau sab polymer muaj qhov cuam tshuam loj rau cov dej txo qis thiab poob qis, uas tuaj yeem cuam tshuam qhov poob qis mus rau qhov loj.

Raws li feem ntau polycarboxylate superplasticizer macromonomer, cov qauv molecular ntawm HPEG2400 yog raws li hauv qab no:
CH2=CH(CH3) (OCH2CH2)n OH

Nws yog tau los ntawm allyl cawv raws li tus neeg sawv cev pib, nyob rau hauv alkali catalytic tej yam kev mob, thiab ethylene oxide nplhaib-qhib ntxiv, yog li nws tseem hu ua allyl cawv ethoxyethylene ether. Nws muaj cov yam ntxwv zoo ib yam li peb cov surfactants feem ntau siv hauv kev tu thiab lwm qhov chaw, xws li cov roj ntsha cawv ethoxyethylene ether AEO thiab MOA, yog li nws tuaj yeem hu ua surfactant. Tom qab ntawd, nws yog siv los ua ib qho kev pib ua rau cov kua qaub tsis txaus xws li acrylic acid thiab maleic anhydride kom tau txais polycarboxylic acid superplasticizer.
Nws cov txheej txheem ntawm kev ua haujlwm kuj zoo ib yam li cov surfactants: nws cuam tshuam lossis rhuav tshem cov qauv flocculation ntawm cov cement hais los ntawm surfactant kev ua, complexation, electrostatic repulsion thiab stereo-repulsion. Lub dispersion thiab stabilization nyhuv ntawm polycarboxylate superplasticizer feem ntau yog tshwm sim los ntawm kev sib cuam tshuam ntawm steric hindrance thiab electrostatic repulsion. Ntawm lawv, electrostatic repulsion muab thawj dispersion thiab steric hindrance muab ndlwg tuav.

Nyob rau hauv cov txheej txheem synthesis, propylene oxide ntu tau qhia, thiab cov molecule hloov ntawm polyoxyethylene qauv mus rau polyether qauv. Vim muaj coob tus ceg saw hlau coj los rau hauv propylene oxide ntu, polycarboxylate superplasticizer uas ua los ntawm TPEG muaj qee yam zoo dua HPEG raws li tus nqi txo cov dej thiab kev khaws cia.
2. Kev sib piv ntawm kev ua tau zoo ntawm ntau hom superplasticizers

3. Cov yam ntxwv ntawm kev ua tau zoo ntawm polycarboxylic acid superplasticizer 1, cov ntsiab lus khoom 38-40%, PH6-7, tsawg npaum li cas, dej txo tus nqi siab, dej txo tus nqi ntau dua 30%;
2. Thaum lub slump yog lub teeb, qhov poob yog me me, thiab cov slump poob tus nqi ntawm cov pob zeb npaj txhij yog tsawg dua 5% hauv 1h thiab tsawg dua 10% hauv 2h;
3. Cov txiaj ntsig kev txhim kho yog qhov tseem ceeb, 3D compressive lub zog ntawm pob zeb yog nce los ntawm 50 ~ 110%, 28D compressive zog yog nce los ntawm 40 ~ 80%, thiab 90D compressive zog yog nce los ntawm 30 ~ 60%;
4. Kev ua haujlwm ntawm cov pob zeb ua tau zoo heev, tsis muaj kev sib cais thiab cov dej xau, thiab cov tsos thiab xim ntawm cov pob zeb yog ib yam. Thaum siv los npaj cov pob zeb qib siab, cov pob zeb muaj kev sib koom ua ke zoo thiab yooj yim rau kev sib xyaw;
5. Cov roj cov ntsiab lus yog nruab nrab, tsis muaj qhov cuam tshuam rau lub elastic modulus ntawm pob zeb, thiab Frost kuj thiab durability yog zoo;
6. Nws tuaj yeem txo cov cua sov ntawm hydration thaum ntxov ntawm cov cement, uas yog qhov tsim nyog rau cov pob zeb loj thiab kev tsim kho lub caij ntuj sov;
7. Kev hloov tau zoo heev, kev sib raug zoo ntawm cov cement thiab cov khoom sib xyaw, kev hloov pauv kub zoo, thiab kev sib raug zoo nrog ntau yam ntawm cov cement thiab admixture;
8. Tsawg shrinkage, uas tuaj yeem txo qhov shrinkage ntawm pob zeb, thiab khov-thaw kuj thiab carbonization kuj zoo dua li cov pob zeb zoo tib yam; Tseem ceeb txhim kho lub volumetric stability thiab lub sij hawm ntev durability ntawm pob zeb;
9. Cov ntsiab lus alkali tsawg heev, thiab cov ntsiab lus alkali tsawg dua lossis sib npaug ntawm 0.2%, uas tuaj yeem tiv thaiv qhov tshwm sim ntawm alkali aggregate cov tshuaj tiv thaiv;
10. Cov khoom muaj kev ruaj ntseg zoo, tsis muaj stratification thiab nag lossis daus tshwm sim tshwm sim thaum lub sij hawm ntev cia, thiab tsis muaj crystallization nag lossis daus ntawm qhov kub thiab txias;
11. Cov khoom yog ntsuab thiab ib puag ncig tus phooj ywg, tsis muaj formaldehyde, thiab yog ib tug phooj ywg environmentally khoom;
12. Cov txiaj ntsig kev lag luam yog qhov zoo, cov nqi sib tw ntawm qhov project yog qis dua li lwm hom khoom, thiab cov cement tuaj yeem txuag tau los ntawm 15-25% raws li tib lub zog.

3. Kev ua lag luam outlook

Kev txiav txim los ntawm qhov teeb meem kev lag luam tam sim no, Tuam Tshoj qhov kev thov txhua xyoo rau polycarboxylic acid superplasticizers yog nruab nrab ntawm 4 lab tons ~ 5 lab tons. Nyob rau tib lub sijhawm, nrog kev nqis peev tsis tu ncua hauv cov haujlwm loj ntawm tsoomfwv hauv tebchaws xws li kev tsheb ciav hlau ceev thiab subway, qhov kev thov tau nce tsis tu ncua. Raws li ib qho tseem ceeb raw khoom rau synthesis ntawm superplasticizers, qhov kev thov rau loj monomers ntawm superplasticizers yog hais txog 600, 000 tons ib xyoo. Cov xwm txheej zoo xws li kev lag luam loj, cov txheej txheem synthesis yooj yim, tsim nyog rau kev tsim khoom loj, tus nqi qis, thiab kev tiv thaiv ib puag ncig ntsuab tau ua rau polycarboxylic acid superplasticizers tsim sai.