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Polycarboxylate superplasticizer is an important class of concrete chemical admixtures, having a comb-like molecular structure, capable of uniformly dispersing cement particles, and the low dosage, maintaining good slump performance. Macromonomer at home and abroad with the Polycarboxylate poor product performance and stability is poor, it is necessary to its system. Firstly, to determine the material of the propylene-based unsaturated double bond content of the measuring method, followed by optimization of the reaction conditions of the synthesis of methoxy polyethylene glycol methacrylate; then each of the methoxy polyethylene glycol methacrylate ester, and methyl alkenyl polyoxyethylene, polyoxypropylene ether as a macromer, investigated the synthesis recipe and reaction conditions, under optimal conditions, random copolymerization of the quaternary system of the Polycarboxylate PC-1 and PC -2, and measuring the product performance; final study polycarboxylate superplasticizer with a variety of surface active agent compound. The main contents and conclusions are as follows: 1. Investigated the three measurement propylene substances unsaturated double bond content draw tribromo method is the best method. Optimization of the unsaturated double bonds the tribromo Determination of methacrylic acid (MAA), deionized water as solvent, 45oC reaction 30 min, MAA recovery of up to 99.22%, the relative standard deviation of 2.42 ‰. 2 to methacrylic acid (MAA) and methoxy polyethylene glycol (MPEG) as raw material, in the catalyst of the role of p-toluenesulfonic acid (p-TSA) and the polymerization inhibitor T methoxy polyethylene glycol, synthetic alcohol methacrylate esters (MPEGMA). Obtained by single factor experiments investigated the optimum synthesis conditions: 140oC 6% (w / w) barrier polymerization inhibitor T, 2% (w / w) p-TSA, N (MAA): n (MPEG) = 3: 1,30% (w / w) of benzene were added, reaction for 8 h. Under the above conditions, the esterification rate reached 93.54%. Methoxy polyethylene glycol methacrylate (MPEGMA), acrylic acid (AA), Sodium methallyl sulfonate (SMS), and methyl acrylate (MA) as the raw material, in the ammonium persulfate (APS) initiator random copolymer synthesized under four polycarboxylate superplasticizer. Polycarboxylate superplasticizer derived by single factor and orthogonal experiment the optimal synthesis conditions: 85oC, 0.7% APS, n (SMS): n (MPEGMA): n (MA): n (AA) = 17:8 : 6:69,8 h. Resulting product PC-1 (0.6% ash, water-cement ratio 0.3) initial grout flow reached 322 mm; the superplasticizer product PC-1 stable performance, four months after its initial grout fluidity only a decrease of 2.4%, but maintain performance of 88.7% of the initial paste fluidity the 2 h grout fluidity. Also superplasticizer number average molecular weight of the dispersion properties prepared of MPEGMA-AA-MA-SMS four yuan system superplasticizer number average molecular mass distribution at 50000-55000, Product dispersed better performance, PC -1 number average molecular mass of 52,800, molecular weight distribution was 1.27. 4 In order to enhance the retention performance of the superplasticizer product, methyl alkenyl polyoxyethylene polyoxypropylene ether (OXAC-608) is a macromonomer synthesized four polycarboxylate superplasticizer. Polycarboxylate superplasticizer derived by single factor and orthogonal experiment the optimal synthesis conditions: 85oC, 1.1% APS, n (SMS): n (OXAC-608): n (MA): n (AA) = 20 : 8:8:64. The resulting product, PC-2 (0.6% dosage, water-cement ratio 0.3) initial paste fluidity reach 320 mm; the superplasticizer product PC-2 stable performance, measured 4 months after its initial paste fluidity fell by only 1.0%, compared to the PC-1, 1.4%; maintain performance has increased dramatically to 93.8% of the initial paste fluidity the 2 h grout fluidity compared to the 5.1% increase in PC-1. The ester bond macromonomer superplasticizer ether bond macromonomer alternative method can effectively improve the superplasticizer maintain performance. Further, the the homemade-superplasticizer product PC-1 and PC-2 with a commercially available four polycarboxylate superplasticizer products for comparison, its dispersion properties significantly better than commercially available products. Dispersed in order to improve the product at a lower cost to maintain performance, homemade polycarboxylate superplasticizer product PC-1, respectively, with an anionic, cationic and non-ionic surfactant compound. Tween-80 complex is best superplasticizer products can improve the dispersibility of the PC-1, and to maintain performance. Tween-80 best added in an amount of 10% (w / w), complex after 1.5 h and 2.0 h, paste fluidity phase alone superplasticizer PC-1 were increased by 10% and 11%.
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