What is polycarboxylate superplasticizer? What are the uses of polycarboxylate superplasticizer?

What is polycarboxylate superplasticizer? What are the uses of polycarboxylate superplasticizer?

In many concrete projects, traditional high-efficiency concrete such as naphthalene series is increasingly unable to meet the needs of projects due to the limitation of technical performance. The new generation of water reducer has attracted much attention at home and abroad, and it is polycarboxylate ether-based high-performance water reducer. What is polycarboxylate superplasticizer? What are the uses of polycarboxylate superplasticizer?

Polycarboxylate superplasticizer is a high-performance superplasticizer and cement dispersant, which is used in cement concrete. Widely used in highways, bridges, dams, tunnels, high-rise buildings and other projects. The product is green and environmentally friendly, non-flammable and non-explosive, and can be safely transported by train and car. According to different main chain structures, polycarboxylate superplasticizer products can be divided into two categories: one is based on acrylic acid or methacrylic acid as the main chain, grafted with polyethers of different side chain lengths. The other is a polyether with different side chain lengths branched with maleic anhydride as the main chain. On this basis, a series of high-performance water reducer products with different characteristics are derived. Before the appearance of polycarboxylic acid admixtures, there were lignosulfonate admixtures, naphthalene sulfonate formaldehyde condensates, melamine formaldehyde condensates, sulfamate formaldehyde condensates, etc. In the early 1980s, Japan took the lead in successfully developing polycarboxylate superplasticizer. The new generation of polycarboxylate superplasticizer overcomes some disadvantages of traditional superplasticizers, and has the advantages of less dosage, good slump retention, low concrete shrinkage, strong molecular structure adjustability, great performance potential, and great production potential, etc. Advantages, the process does not use formaldehyde and other outstanding advantages.

The difference between polycarboxylate-based water-reducers and naphthalene-based water-reducers lies in: first, the diversity and adjustability of the molecular structure; . From the point of view of the mechanism of action, the molecular structure of polycarboxylate superplasticizer is comb-shaped, and the strong polar anion "anchor" group on the main chain is adsorbed on the cement particles, and the outwardly extending comb-like structure is supported by many branch chains. The tooth-shaped structure provides sufficient spatial arrangement effect for the further dispersion of cement particles. Compared with the electric repulsion of the naphthalene-based superplasticizer bilayer, the steric hindrance keeps the dispersion for a longer time. Properly changing the comb-like structure of polycarboxylate superplasticizer, and appropriately changing the density and length of side chains, can obtain high water-reducing and high-early-strength superplasticizers suitable for prefabricated components. Polycarboxylate superplasticizer can adjust and change the molecular structure according to needs to achieve the purpose of changing performance, rather than simple compound modification.