Study On Synthesis And Application Of Polycarboxylate Superplasticizer

Polycarboxylate superplasticizer?PC?because of its excellent performance and green which gets the favour of engineering,once became the lead product in PC industry research.Now,the raw materials of concrete are widely distributed and the quality is different in our country.The concrete performance required by the project is not identical,it's essential to choose suitable PC mother liquor,and compounding technology is very important.By single factor experiment,the influence of different process parameters on the properties of the PC have been studied and The optimum synthesis process was determined.Then the research on compounding technology of C60 segment concrete and C30 pre-mixed concrete in commercial concrete mixing station have been done.The main conclusions are as follows:?1?With methyl allyl polyoxyethylene ether?HPEG?and acrylic acid?AA?as monomer,with H₂O₂-Vc as redox initiator system,ether-type Polycarboxylate superplasticizer was synthesized by radical polymerization.According to the initial fluidity and fluidity loss of cement paste,the best processing technology was that the molar ratio of AA to HPEG was 4.5,n?H₂O₂?:n?Vc?=7.0:1,the dosage of inititor?Vc?was 0.13 wt%,chain transfer agent was 0.47 wt%,copolymerization temperature was50?.The PC had best dispersion and dispersion retention under the condition of the synthesis,it also had well compatibility of Gansu Qilianshan cement,the processing technology and the PC mother liquor both were very stable.?2?The compound formula of water reducer for the C60 segment concrete was PC mother liquor and defoaming agent were 28 g and 0.05 g,water was 71.95 g,which met the working performance and the mechanical properties of the concrete.?3?The compound formula of water reducer for the C30 pre-mixed concrete in commercial concrete mixing station was PC mother liquor and PC-501 mother liquor were 19.5 g and 9 g,sodium gluconate and sodium dodecyl sulfonate were 5 g and0.05g,water was 66.45 g,which met the working performance and the mechanical properties of the concrete.?4?The equipment of compounding water reducer is relatively simple and it is easy to operate.To avoid the phenomenon of undermixing and layering,so the circulation time of the liquid mixture is not less than 30 minutes.The water reducer product can be stored in plastic cans and keep it in cool and ventilated place.