Views: 12 Author: su Publish Time: 2018-11-05 Origin: Site
Polycarboxylate superplasticizer is a kind of cement dispersant used in cement concrete. The early development of the product is a polyester structure with a main chain of methacrylic acid and a side chain of carboxylic acid groups. The polyether structure in which the main chain is a polymerized acrylic acid and the side chain is a polyether, the polycarboxylate water reducing agent is a hydrophilic long side chain having a certain length and number and a main group having a strong polar active group A special molecular structure surfactant composed of chains.
In order to effectively improve the fresh mix performance of concrete, the polycarboxylate water reducer product suitable for on-site concrete use, in addition to the mother liquor synthesis process, it is also necessary to improve the concrete by adding some functional components for simple physical compounding. Construction properties such as retardation, gas content, workability and appearance. The physical compounding of retarders is indispensable. The addition of retarding component is an important component for adjusting the admixture to adapt to different air temperature setting time. Under the allowed conditions, one or more retarding agents may be used together (commonly used sodium gluconate, citric acid, phosphate, sugar) , lignosulfonate, etc.), especially sodium gluconate and sugars have good adaptability. The dosage of retarder is adjusted with temperature, and the addition of sodium gluconate is more effective. Sometimes adding some retarder is beneficial to reduce slump loss, but it can not be used as a more effective method to inhibit caries. The synthesis and application technology of carboxylic acid-based high-performance water-reducing agent has developed rapidly. Polyether-type polycarboxylate water-reducing agent has become a major variety, and serialized polyether-type polycarboxylate water-reducing agent obtained by the change of synthesis method has been proved by practice. Products, have been able to meet different needs. Polymeric ether macromonomers have different kinds of end-capping groups, and there are also molecular weight changes. The quality and type of monomers determine the final product of polycarboxylate synthesis. At present, there are no new monomers appearing for about 5 years. The starting group functional polyether monomer and the development of refined polyether varieties should be the preferred topic for the monomer manufacturer. . Polyether type water reducing agent can be synthesized by using polyether monomer, various functional groups to assist the main chain design and production process changes, to obtain a variety of excellent mother liquor products. Polycarboxylate water reducing agent compounding scheme The combination of different mother liquors including polycarboxylate water reducing agent, and the physical compounding of polycarboxylate mother liquor with functional components such as retardation, bleed air, defoaming, state regulation, and mud resistance. The combination of the mother liquor and the different functional mother liquors is the basis of the compounding technique, followed by additional functions. The fines are fine-tuned to obtain satisfactory concrete properties.