Research On Polycarboxylic Acid Type High Performance Concrete Water-reducer

This article research work take the country "973" the plan project "High performance Cement Preparation And Application Basic research" the sub- topic chemistry sur- medicinal preparation to the high performance cement hydration advancement influence as a background, discussed the synthesis craft of third generation high performance concrete water reducer:1 .The methylacrylic acid and the different molecular weight polyethylene glycol single armor ether ester used the azeotropy distillation to synthesize a series of macro-molecules monomer methylacrylic acid polyethylene glycol single armor ether ester (MAAMPEA), anti- discussed the methylacrylic acid to gather the mechanism, catalyzes the mechanism, has studied influence conversion rate each factor, and has carried on the infrared analysis, has determined its best synthesis craft condition: The polyethylene glycol single methyl ether (MPEG) and the methylacrylic acid (MAA) a mole of ratio is: (1.15 ~ 1.2): 1;The polymerization retarder selects the hydroquinone, the armor quinone compound use or the independent employment, PN;The catalyst selects to the toluene sulfonic acid, the amount used for the reactant lumpy mass 5 ~ 6%;The including water medicinal preparation selects the toluene, the amount used for a reactant lumpy mass time;Under this condition synthesizes the methylacrylic acid polyethylene glycol single armor ether ester (MAAMPEA) the esterification rate to be possible to achieve 98.9%.2.With the self-made macro-molecule monomer methylacrylic acid polyethylene glycol single armor ether ester (MAAMPEA), the methylacrylic acid (MAA) with 2 -acrylic amides - 2 methyl propyl sulfonic acid sodium (AMPS) the radical polymerization, a series of synthesized dual, three copolymer, studied the copolymer to water-reducer the structure, the composition and so on halves disperses the performance the influence, and has carried on the infrared analysis. The experimental structure indicated that, When monomer MAAMPEA: MAA mole of ratio 1:3, When a AMPS mole of score is 10%, this copolymer has the good dispersivity and the dispersive retentivity. At the same time the best response condition has been determined: The initiator selects the ammonium persulfate, the amount used for thereactant weight 5 ~ 7%;The temperature is 80 °C;The reaction time is 7 ~ 8h;The copolymer molecular structure and the overseas similar product are close.3.Through gathers the carboxylic acid to the synthesis is reduces water medicinal preparation a series of concrete, the cement experiment, finally indicated the self-restraint gathers polycarboxylic acid type water-reducer have the good dispersivity and the dispersive retentivity, the configuration concrete has the good fluidity and the fluid retentivity;when Mixing 1% of the concrete the quantity, the water reducing rate is possible to achieve 25%, performance much better than naphthalene type water-reducer, almost the same as overseas similar product performance.