2024-07-15- readingsVinyl Acetate Ethylene Copolymer (VAE) emulsion plays a vital role in tile adhesives, mainly in improving bonding strength, enhancing flexibility, improving construction performance and enhancing durability. The following is a detailed discussion of VAE's chemical properties, mechanism of action and specific applications in tile adhesives.
### 1. Chemical properties of VAE and its basic role in tile adhesives
#### 1. Basic properties of VAE
VAE is a polymer emulsion copolymerized by vinyl acetate (VAc) and ethylene (E). Its molecular structure contains both the polar ester group of vinyl acetate and the non-polar hydrocarbon group of ethylene. This structure makes VAE have the excellent properties of both polar and non-polar materials.
#### 2. The main role of VAE in tile adhesives
- **Improving bonding strength**: VAE can significantly enhance the bonding force of the adhesive, forming a strong bond between the tile and the substrate.
- **Enhanced flexibility**: VAE gives the adhesive higher flexibility, reducing cracking and falling off caused by thermal expansion and contraction or slight deformation of the substrate.
- **Improved construction performance**: VAE can improve the handling performance of the adhesive, making it easier to apply and adjust.
- **Improved durability**: VAE can improve the anti-aging and weather resistance of the adhesive and extend its service life.
### 2. The specific mechanism of VAE in tile adhesives
#### 1. Mechanism of improving bonding strength
The vinyl acetate group in the VAE emulsion can react with calcium hydroxide (Ca(OH)2) in the cement hydration product to form a strong chemical bond. At the same time, the ethylene component in VAE can provide good cohesion, giving the adhesive higher bonding strength and stability.
- **Chemical bonding**: The ester group in VAE can form calcium salts with calcium ions in the cement hydration product to increase bonding strength.
- **Cohesion**: The ethylene component in VAE can improve the cohesion of the adhesive and enhance its overall strength.
#### 2. Mechanism of enhancing flexibility
The ethylene component in VAE has good flexibility and can give the adhesive a higher elastic modulus and elongation at break. This allows the adhesive to maintain good adhesion and stability when dealing with slight deformation and thermal expansion and contraction of the substrate, reducing the risk of cracking and falling off.
- **Elastic modulus**: VAE gives the adhesive a lower elastic modulus and improves its deformation ability.
- **Elongation at break**: VAE can significantly increase the elongation at break of the adhesive and improve its crack resistance.
#### 3. Mechanism of improving construction performance
VAE emulsion can significantly improve the fluidity and thixotropy of the adhesive, making it easier to apply and adjust during construction. At the same time, the lubricating effect of VAE can reduce friction during construction and improve construction efficiency and quality.
- **Fluidity**: VAE can improve the fluidity of the adhesive and make it easy to apply.
- **Thixotropy**: VAE can give the adhesive good thixotropy, remain stable when stationary, and be easy to adjust during construction.
- **Lubricity**: The lubricating effect of VAE can reduce construction friction and improve construction efficiency.
#### 4. Mechanisms for improving durability
VAE emulsion can significantly improve the weather resistance and anti-aging properties of the adhesive. The ethylene component contained in its molecular structure can improve the adhesive's resistance to ultraviolet rays and oxidation, and extend its service life. In addition, VAE can improve the adhesive's resistance to freeze-thaw cycles and ensure its stability in various harsh environments.
- **UV resistance**: The ethylene component in VAE can improve the adhesive's resistance to ultraviolet rays and reduce the degradation of the adhesive by ultraviolet rays.
- **Antioxidation**: VAE can improve the adhesive's antioxidant capacity and delay its aging process.
- **Freeze-thaw resistance**: VAE can improve the adhesive's resistance to freeze-thaw cycles and prevent damage caused by freeze-thaw cycles in low temperature environments.
### III. Application of VAE in Tile Adhesives
#### 1. Application Scope
VAE emulsion is widely used in various types of tile adhesives, especially in the following occasions:
- **Indoor and outdoor tile paving**: VAE can provide excellent bonding strength and weather resistance, suitable for tile paving in various indoor and outdoor environments.
- **Heavy and large-sized tiles**: VAE can enhance the bonding strength and flexibility of the adhesive, suitable for the bonding of heavy and large-sized tiles.
- **High and low temperature environments**: VAE's weather resistance and anti-freeze-thaw ability make it suitable for tile paving in high and low temperature environments.
#### 2. Formula design
In the formula design of tile adhesives, the amount of VAE emulsion added needs to be adjusted according to the specific application requirements. Generally, the amount of VAE emulsion added is between 5% and 20%, and the specific formula design needs to consider the following factors:
- **Bond strength**: According to the required bond strength, adjust the amount of VAE added to ensure that the adhesive can provide sufficient bonding force.
- **Flexibility**: According to the required flexibility, the amount of VAE added is adjusted to ensure that the adhesive can cope with the slight deformation and thermal expansion and contraction of the substrate.
- **Construction performance**: According to the construction requirements, the amount of VAE added is adjusted to ensure that the adhesive has good fluidity and thixotropy for easy construction.
- **Durability**: According to the requirements of the use environment, the amount of VAE added is adjusted to ensure that the adhesive has excellent weather resistance and freeze-thaw resistance.
### Conclusion
VAE plays a key role in tile adhesives. It significantly improves the overall performance of tile adhesives by increasing bond strength, enhancing flexibility, improving construction performance and improving durability. The unique chemical properties and action mechanism of VAE emulsions make it an important ingredient in modern tile adhesive formulations. Through the scientific and rational application of VAE emulsions, it can ensure that tile adhesives provide excellent bonding effects and long-term stability in various complex environments and application conditions, meeting the high quality requirements of modern construction projects.
