The synthesis technique of polyacrylic acid superplasticizer

Abstract

Using water separation technique, acrylic acid (AA) and polyethylene glycol (PEG) 1000, of which the ratio was 1.5, were esterified and the optimum esterification ratio of 90% could be reached under the condition of 110 ℃×3 h. Using polyoxyethylene acrylate macromonomer (PA) prepared in the esterification, AA and sodium methylacryl sulfonate (MAS) as monomers, a copolymer which could be used as superplasticizer was prepared by free radical copolymerization in n(PA)∶n(AA)∶n(MAS) of 1∶7∶3. When the synthesis condition was 80 ℃× 5 h, the optimal dosage of initiator was 3.0%-4.0%, the fluidity of cement paste with the samples could reach 270 mm. By analyzing the effect of the content of residual small molecule sulfonic monomer on the properties of sample, n(MAS)/n(PA) was controlled in a range of 2.5-3.8.

A Thermodynamic Model for Representation Reaction Abilities of Structural Units in Full Composition Range of Fe–Si Binary Melts Based on the Atom–Molecule Coexistence Theory

“…However, the investigation of thermodynamic modeling on Fe–Si binary melts at about 1873 K is not sufficient currently. It has become a consensus1, 40, 42, 44–49 that four kinds of stoichiometrically intermetallic compounds of Fe 2 Si, Fe 5 Si 3 , FeSi, and FeSi 2 constitute the equilibrium phases according to Fe–Si binary phase diagram 39, 53, 54. This means that atoms of both Fe and Si, and molecules of Fe 2 Si, Fe 5 Si 3 , FeSi, and FeSi 2 can coexist in Fe–Si binary melts.…”

“…It has been pointed out by Yang et al50 that the defined mass action concentrations N i of structural units in metallurgical slags50–63 had been verified to reliably represent the reaction abilities of structural units based on the ion and molecule coexistence theory (IMCT),51, 52, 57–63 like the traditionally applied activities a R, i of components in slags relative to pure liquid or solid matters as standard states in the classically metallurgical physicochemistry. Zhang et al51–56 had successfully characterized the mass action concentrations of structural units as atoms or molecules in some metallic melts based on the atom and molecule coexistence theory (AMCT)51–56 for metallic melts, which has the similar principles with the IMCT51, 52, 57–63 for metallurgical slags.…”

Antioxidant activities and chemical profiles of pyroligneous acids from walnut shell

“…Ayguun et al [17] described the method of making activated carbon from bioresources, including the walnut shell. Zhang et al [18] used a customized pyrolytic furnace to produce hydrogen gas from the catalytic pyrolysis of walnut shell. The research focused on the influences of pyrolytic conditions on the yield of hydrogen gas, such as the temperature, the amount of catalyst added.…”

RP-LC Determination of Residual Monomers in Polycarboxylate Superplasticizers

“…Normally, PCs can be prepared by copolymerization of monomers with different functional groups which include carboxylic acid group, sulfonic acid group and long side-chain [2][3][4][5][6]. A variety of researches have proved that residual monomers have significant effect on performance of PCs [7][8][9].…”