Synthesis Method And Characterization Mode Of Polycarboxylic Type Superplasticizer Containing Nitrogen And Sulfur

Polycarboxylic-type surface-active agent containing nitrogent and sulfur (NSPCA) was one kind of Polycarboxylic-type superplasticizer. And it was a modern frontier research subject which was under the copolymerization of carboxyl, unsaturated monomer and others. The NSPCA was characteristic of lower additive, higher fluidiffication effect, environmental protection effect and prevent concrete mix from slump-loss with time duration. So the NSPCA is an excellent water-reducing agent. This paper began to study from the chemical structure, function mechanism and unit structure model of Polycarboxylic-type superplasticizer,and designed the coplymerisation containing three main reactive monomers(MA-XPEG-SMAS), then got a new type of PCA which contained polyoxyethylene, carboxyl and sulfonic.This paper studied the technology conditions of three formulas and determined the optimum one through a lot of single factor experiment and orthogonal test.Three formulas as followed:①MA-DA-SMAS; MA:DA:SMAS=1.0:0.5:0.5 (Mole ratio), 4%K2S2O8, reaction temperature 80℃,reaction time 5 hour,initial net fluidity 240mm;②MA-XPEG-MPS; MA:XPEG:SMAS=1.0:0.2:0.2,the mixed quantity of K2S2O8 2%, reaction temperature 70℃, reaction time 3 hours, dosage of 0.3%, can achieve maximum fluidity 345mm, and initial net fluidity and scattered had good performance. But during the testing of cement slurry flow degrees after 60min, we found the phenomenon containing shedding water quickly, layering obviously,bottom harden, workability poor.③MA-XPEG-SSS; MA:XPEG:SSS=1.0:0.2:0.35, can markedly improved the problems of second technology, although initial net fluidity declined from about 345mm to 330mm or so, but workability was still great.The structures were characterized by infrared spectrum, and the consequence was good and realized the molecular structure of the basic consistent assumptions. From cement and concrete performance experiment, it showed that MA-XPEG(2)-SSS PCA had good adaptability, mixing content of 0.3%, water-cement ratio of 0.29, cement initial net fluidity 331mm, 326mm after 60min, decreasing-water rate can reach 26%, initial slump of 230mm, 218mm after 60min for the slump, minimal losses corresponding to the compressive strength 147%.