Poly carboxylic acid niam cov dej cawv txo tus neeg sawv cev yog ib hom qauv tsim qauv ntawm cov copolymer muaj cov kab mob carboxyl nto active tus neeg sawv cev, zwm rau lub cim thib peb ntawm cov dej siab ua kom muaj zog txo tus neeg sawv cev rau cawv, qhov kev ua tau zoo tshaj plaws, yog kev tsim ntau yam muaj zog ntawm qib qib ntawm pob zeb thiab cov cheebtsam ntawm cov khoom siv zoo ntxiv, tshwj xeeb tshaj yog tsim rau cov pob zeb ua kom muaj zog, ua kom muaj zog, ua vaj tse, nws tus kheej pob zeb ua ke thiab pob zeb. Nws tuaj yeem siv dav hauv kev lag luam thiab kev tsim kho vaj tsev, dej txuag dej thiab dej num ua dej num, txoj kev tsheb thiab txuas hniav thiab lwm yam teb.Yuav ua li cas hluavtaws niam cawv ntawm polycarboxylate superplasticizer?
(1) loj monomer copolymerization txujci: ncaj qha siv thawj npaj ntawm lub zog loj monomers (piv txwv li, methoxy polyethylene glycol methacrylate), nrog qee qhov sib piv ntawm cov monomers xws li acrylic, methyl methacrylate, methyl allyl sulfonate) sib xyaw ua ke ncaj qha los ntawm kev daws teeb meem polymerization, hluavtaws cov dej txo tus neeg sawv cev cov khoom lag luam zoo yog qhov ruaj khov, cov qauv ntawm cov qauv ntawm cov khoom noj khoom haus zoo, tab sis lub premise yog coj los ua ke ntawm monomer, cov txheej txheem ua kom huv si yog trival, tus nqi siab;
(1) loj monomer copolymerization txujci: ncaj qha siv thawj npaj ntawm lub zog loj monomers (piv txwv li, methoxy polyethylene glycol methacrylate), nrog qee qhov sib piv ntawm cov monomers xws li acrylic, methyl methacrylate, methyl allyl sulfonate) sib xyaw ua ke ncaj qha los ntawm kev daws teeb meem polymerization, hluavtaws cov dej txo tus neeg sawv cev cov khoom lag luam zoo yog ruaj khov, cov qauv ntawm cov qauv ntawm cov khoom noj khoom haus zoo, tab sis lub premise yog coj los ua ke ntawm monomer, txheej nruab nrab kev ua kom huv si yog trival, nqi siab; lub monomer loj loj cuam tshuam ncaj qha rau qhov ruaj ntseg ntawm qhov zoo tshaj plaws ntawm qhov dej kawg-txo tus neeg sawv cev thiab cov nyhav molecular ntawm lub polymer tsis yooj yim los tswj.
(2) cov txheej txheem tom qab ua haujlwm polymerization: cov polymers uas twb muaj lawm siv rau kev hloov kho. Feem ntau, polycarboxylic acid nrog paub molecular phaus yog saws. Nyob rau hauv qhov kev ua ntawm catalyst, nws tau sib tsoo nrog polyether los ntawm esterification cov tshuaj tiv thaiv ntawm qhov kub nce siab.Txawm li cas los xij, vim muaj qhov txwv muaj cov khoom lag luam polycarboxylic acid thiab cov ntsiab lus tshwj xeeb, nws tsis yooj yim los kho nws cov muaj pes tsawg leeg thiab cov hnyav molecular.Thaum tib lub sijhawm, kev sib xyaw ntawm polycarboxylic acid thiab polyether tsis zoo, thiab cov tshuaj esterification yog qhov nyuaj hauv kev xyaum. Tsis tas li ntawd, nrog cov esterification txuas ntxiv, dej yuav txuas ntxiv kom dim, theem sib cais yuav tshwm sim. Tam sim no, ib qho zoo polyether soluble nrog polycarboxylic acid tsis tau pom.
(3) hauv-polymerization thiab grafting: carboxylic unsaturated monomers (xws li acrylic kua qaub, polyethylene glycol, thiab lwm yam) yog siv los ua cov tshuaj tiv thaiv nruab nrab kom sib sau thiab esterify. Cov txheej txheem yooj yim, cov nqi tsim tawm yog tsawg, thiab lub cev molecular ntawm cov polymer tuaj yeem tswj tau tib lub sijhawm.Tiam sis, cov saw tseem ceeb tsuas tuaj yeem xaiv cov monomers uas muaj -cooh pab pawg, txwv tsis pub nws nyuaj rau kev coj txhom. Ntxiv mus, kev sib tsoo cov tshuaj tiv thaiv no yog qhov tshuaj tiv thaiv thim rov qab sib luag. Twb muaj dej ntau nyob rau hauv cov tshuaj tiv thaiv, yog li cov ntsuas ntawm kev sib tsoo tsis ntau thiab nws yog qhov nyuaj rau kev tswj hwm.
