Industrialization And Application Of Poly(Styrene-butadiene) Specialized For Cement Concrete

The polymer/cement concrete composite has many more advantages such as corrosion-resistance, excellent solidified properties and so on than that of normal cement concrete. Polymer latex seems quite convenient to be uniformly infiltrated into cement concrete so that the hollow structure of the cement concrete could be efficiently decreased. Thus the composite of cement concrete adding polymer latex exhibits good performance such as crease-strength, impervious-strength, tensile-strength, compression-strength and so on. The application of polymer/cement concrete composite on the construction of road, bridge and under-ground installation as well as the treatment of the corrosion-preventive surface in China was rapidly increased. Especially, the cement concrete with the addition of Poly (Sty rene-Butadiene) (SB) latex shows an outstanding prospect in market.In this article, the engineering problems of the industrialization of SB latex as cement additive and its application were studied. The article includes four chapters as follows:The first chapter summarized the domestic and international research progress on SB latex. The polymerizing technology process of SB was reviewed and the engineering factors involving the stirring speed, heat transfer and scale-up were summarized and discussed. Our research plan was thus proposed.The second chapter studied the influence of engineering factors relevant to the industrialized process of SB latex used as an additive of cement concrete. The pilot-trial technological recipe and process character of SB polymerization was emphatically analyzed. On the base of the considering of the industrialization of normal SB later product, the constant unit volume power (Pv) was mainly selected as a rule to scale up the polymerization reactor during the industrialization of SB latex as cement additive. Then the industrial experiments were carried on to examine the effects of the stirring speed and shape of stirrer as well as inner paddle on the production process and colloidal properties of SB latex. Additionally, the feasibility of heat transfer in the 20m3 industrial polymerization reactor was analyzed and discussed. It was shown that the scale-up rule combined the near-same unit volume power (Pv=0.5~0.6) with the near-same tip-shear rate should be applicable, and the experimental results indicate that the polymerization outcomes in the 20m3industrial reactor were same as those of 2m3 pilot plant. The areas of heat transfer via inner-cooling vessel and jacket in the 20m3 industrial polymerization reactor were enough due to the successive feed mode in polymerization procedure of SB latex production. Furthermore, the SB latex with small particle-size, narrow particle-size distribution and good stability could be produced with the control of the pace of stirring during the polymerization.The third chapter studied the applied properties of industrial SB latexes as cement additive. The compression-strength, tensile-strength and impervious-strength of the cement concrete and so on were determined, and the effects of different industrialized SB latex products on the properties of SB/cement concrete were examined. The experimental results indicate that the industrialized SB latex products have same qualities as those of pilot-trial products. This means that the scale up of polymerization process from 2m3 pilot plant to 20m3 industrial reactor was quite successfulThe fourth chapter concluded the research work.