Polycarboxylate water reducer is a high-performance water reducer commonly used in cement concrete, also known as cement dispersant. It is commonly used in construction projects such as highways and bridges. So, how is polycarboxylate water reducer synthesized
Let's take a look, editor.
In the synthesis of polycarboxylate superplasticizer monomers, the design of molecular structure is very important, including main chain groups, side chain density, and side chain length. The main synthesis methods include in-situ polymerization grafting, polymerization followed by functionalization, and direct monomer copolymerization.
1. In situ graft copolymerization
Polyether is used as the medium for unsaturated monomer polymerization. Simultaneously carried out main chain aggregation and side chain introduction. The process is simple, and the molecular weight of the synthesized water reducing agent can be controlled within a certain range. However, the esterification reaction involved in this method of polycarboxylate superplasticizer equipment is reversible, and the grafting rate is relatively low in aqueous solution, which has gradually been eliminated.
2. Functionalization after aggregation
The main method of this visit is to first synthesize the main chain of the water reducing agent, and then introduce side chains for functionalization through other methods. This method is difficult to operate, the molecular structure of the water reducing agent is not flexible, and the compatibility between monomers is poor, which greatly limits its application.
3. Direct copolymerization of monomers
This method first prepares active macromonomers, and then polymerizes them in an aqueous solution using an initiator. With the development of macromolecular monomer synthesis technology, there are more and more types of macromolecular monomers. The equipment for synthesizing polycarboxylate superplasticizers has become the most commonly used method in the production of polyacetic acid high-efficiency superplasticizers.
