Synthetic Materials Thiab Technology Ntawm Polycarboxylic Superplasticizer

Polycarboxylic superplasticizer yog comb-shaped polymer surfactant synthesized nyob rau hauv aqueous tov los ntawm dawb radical polymerization. Nws muaj cov macromolecular compounds uas muaj sulfonic, carboxylic, hydroxyl, thiab ether pawg nrog rau polyoxyethylene sab chains. Raws li qhov sib txawv ntawm cov saw tseem ceeb thiab cov saw txuas txuas, polycarboxylic superplasticizers tuaj yeem muab faib ua ob pawg: ib qho nrog acrylic acid lossis methacrylic acid raws li cov saw tseem ceeb, txuas nrog cov saw hlau sib txawv ntawm polyether ntev ntawm ester bonds; lwm yam nrog maleic anhydride raws li cov saw tseem ceeb, txuas nrog sab chains ntawm txawv polyether ntev ntawm ether bonds. Qhov kev faib tawm no tau coj mus rau kev txhim kho ntawm cov kev ua haujlwm siab superplasticizers nrog ntau yam khoom.

Cov txheej txheem tseem ceeb suav nrog hauv-situ grafting polymerization, post-polymerization functionalization, thiab ncaj qha monomer copolymerization. Feem ntau cov tuam txhab hauv peb lub nroog tau txais txoj kev ncaj qha monomer copolymerization txoj kev, cov txheej txheem dawb radical copolymerization uas tso cai rau kev hloov pauv hloov pauv ntawm cov qauv molecular thiab ua rau cov grafting ntawm ntau pawg ua haujlwm. Rau kev tsim khoom, qib siab, paub tab, thiab txhim khu kev qha khoom siv hauv tsev thiab thoob ntiaj teb yog siv, nrog rau cov kev txawj ntse digital siab heev los saib xyuas thiab tswj ntau yam txheej txheem, kom ntseeg tau cov khoom zoo thaum txo cov khoom siv.

Kev npaj cov khoom tseem ceeb

Ua ntej, dej yog ntsuas thiab pumped rau hauv cov tshuaj tiv thaiv kettle. Tom qab ntawd lub agitator pib, thiab cov monomer loj (TPEG) yog manually ntxiv thiab tov nrog dej ntawm ib tug stirring tus nqi ntawm 60 r / min rau li 0.5 teev. Tom ntej no, ntsuas sodium methacrylate sulfonate ntxiv rau cov tshuaj tiv thaiv kettle thiab nplawm li 1 teev. Kev npaj yog ua tiav nyob rau hauv ambient kub thiab siab, thiab cov khoom dissolves tag nrho los tsim cov khoom tseem ceeb. Lub sijhawm tag nrho rau qhov kev npaj no yog kwv yees li 1.5 teev.

Kev Npaj Cov Khoom Pab Txhawb (Cov Khoom A thiab B)

Kev npaj cov khoom A:Cov dej yog ntsuas thiab tso rau hauv A cov khoom sib xyaw tank, thiab cov agitator pib. Ntsuas acrylic acid yog ces ntxiv thiab tov nrog dej ntawm ib tug stirring tus nqi ntawm 60 r / min. Tom qab ntxiv acrylic acid, ntsuas mercaptopropionic acid thiab vitamin C tau txuas ntxiv mus rau lub tank thiab nplawm uniformly. Kev npaj ntawm Cov Khoom A yuav siv sijhawm li 1 teev.

Kev npaj cov khoom B:Cov dej yog ntsuas thiab tso rau hauv B cov khoom sib xyaw tank, thiab cov agitator pib. Ntsuas ammonium persulfate ces muab tso rau hauv lub tank thiab tov nrog dej ntawm ib tug stirring tus nqi ntawm 60 r / min. Kev npaj cov khoom B yuav siv li ntawm 0.5 teev. Ob qho khoom siv yog npaj nyob rau hauv ambient kub thiab siab.

Polymerization Reaction

Thaum tag nrho cov ntaub ntawv raw tau npaj, cov tshuaj tiv thaiv polymerization kettle yog rhuab hluav taws xob. Thaum qhov kub siab tshaj 30 degree, lub polymerization pib nyob rau hauv ambient siab los ntawm dripping cov ntaub ntawv A thiab B rau hauv lub hwj uas muaj cov khoom tseem ceeb. Cov khoom A yog dripped tshaj li ntawm 180 feeb, thiab cov khoom B tshaj li ntawm 210 feeb. Thaum lub sij hawm dripping txheej txheem, qhov ntsuas kub yog saib xyuas kom nws nyob nruab nrab ntawm 40-50 degree. Tom qab ob qho tib si tau ntxiv tag nrho, cov tshuaj tiv thaiv txuas ntxiv nyob rau hauv tib qhov kub thiab txias rau lwm 60 feeb. Lub sijhawm tag nrho rau polymerization yog kwv yees li 5.5 teev.

Alkaline Neutralization

Tom qab polymerization, ntsuas dej thiab sodium hydroxide (khoom) yog ntxiv rau cov tshuaj tiv thaiv kab mob rau cov tshuaj tiv thaiv tsis zoo, uas yuav siv sijhawm kwv yees li 0.5 teev. Tom qab neutralization, pH ntawm cov khoom nyob rau hauv lub kettle yog hloov mus rau ib ncig ntawm 7.