Polyethers are commonly used in the formulation of high-performance polycarboxylic acid water reducers, which are essential components in modern concrete admixtures. These water reducers are added to concrete mixes to improve workability, reduce water content, increase strength, and enhance durability. Polyethers are an important class of chemicals used to achieve these goals.

Here's how polyethers are typically used in conjunction with polycarboxylic acids as water reducers:

1. Polycarboxylic Acid: Polycarboxylic acids, often in the form of their salts, are the primary water-reducing agents in concrete admixtures. They contain carboxylic acid groups that can adsorb onto the surface of cement particles, creating a negatively charged layer that repels other cement particles. This dispersion effect reduces the amount of water needed for a given level of workability, improving concrete strength and durability.

2. Polyether Modification: Polyethers are often added to polycarboxylic acid water reducers to modify their properties and enhance their performance. These polyethers can be used as comb polymers, meaning they have a hydrophilic backbone with hydrophobic side chains. These side chains can interact with the cement particles in a way that complements the action of the polycarboxylic acid.

- Hydrophilic Backbone: The hydrophilic backbone of the polyether can help in dispersing cement particles, similar to the action of the polycarboxylic acid.

- Hydrophobic Side Chains: The hydrophobic side chains can adsorb onto the surface of cement particles, preventing them from flocculating (clumping together) and improving the overall dispersion of the particles.

3. Improved Workability: The combination of polycarboxylic acids and polyethers allows for better control of concrete workability. By reducing the water content required for a given level of flow or slump, these admixtures can improve the handling and placement of concrete without compromising its strength.

4. Strength Enhancement: By reducing the water-cement ratio and promoting a more uniform distribution of cement particles, polycarboxylic acid water reducers with polyethers can lead to improved early and ultimate concrete strength.

5. Durability: Enhanced dispersion and reduced water content can also contribute to the long-term durability of concrete, making it less susceptible to cracking, permeability, and other forms of deterioration.