Process design and optimization of VPEG-PCEs

The VPEG type polycarboxylate superplasticizer (PCE-A) was synthesized by using 4-hydroxybutylvinyl polyoxyethylene ether (VPEG) as macromonomer, hydrogen peroxide (H2O2)\reducing agent (sodium formaldehyde sulfoxylateas) as redox system, and thioglycolic acid as the chain transfer agent. The effects of synthesis temperature, acid-ether ratio and reaction time on the dispersion properties of polycarboxylate superplasticizer were investigated experimentally, and the results showed that the optimal preparation process of PCE-A is n(AA): n(VPEG-4000)=4.4:1, hydrogen peroxide, formaldehyde sodium hydrogen sulfite and thioglycolic acid respectively account for the total mass of VPEG monomer 0.75%, 0.2%, and 0.4%, the optimum synthesis temperature, dripping time, and constant temperature reaction time were 14 °C, 60 min, and 60 min, respectively. The concrete results showed that the dispersibility and slump retention performance of PCE-A were better than the commercially available VPEG type polycarboxylate superplasticizer PCE-W01, PCE-W02 and PCE-W03.