Hydroxyethyl Cellulose (HEC) is a non-ionic water-soluble polymer compound whose chemical structure is modified from cellulose through a hydroxyethylation reaction. HEC has good water solubility, thickening, suspending, emulsifying, dispersing and film-forming properties, so it is widely used in building materials, coatings, daily chemicals and food industry. In spray-coated quick-setting rubber asphalt waterproof coatings, the introduction of hydroxyethyl cellulose can significantly improve its heat resistance.
1. Basic properties of hydroxyethyl cellulose
Hydroxyethylcellulose has efficient thickening and film-forming capabilities in water, making it an ideal thickener for a variety of water-based coatings. It significantly increases the viscosity of the paint by forming hydrogen bonds with water molecules, making the network of water molecules tighter. This property is particularly important in waterproof coatings, as high viscosity helps the coating maintain its shape and thickness before curing, ensuring film consistency and continuity.
2. Mechanism to improve heat resistance
2.1 Increase the stability of coatings
The presence of hydroxyethyl cellulose can improve the thermal stability of rubber asphalt coatings. The viscosity of paints typically decreases when temperatures rise, and hydroxyethyl cellulose slows this process and maintains the paint’s physical properties. This is because the hydroxyethyl group in the HEC molecule can form a physical cross-linked network with other components in the coating, which enhances the thermal stability of the coating film and enables it to maintain good structure and function under high temperature conditions.
2.2 Improve the mechanical properties of the coating film
The mechanical properties of the coating film, such as flexibility, tensile strength, etc., directly affect its performance under high temperature conditions. The introduction of HEC can enhance the mechanical properties of the coating film, which is mainly due to its thickening effect that makes the coating film denser. The dense coating film structure not only improves heat resistance, but also enhances the ability to resist physical stress caused by external thermal expansion and contraction, preventing cracking or peeling of the coating film.
2.3 Enhance the adhesion of the coating film
Under high temperature conditions, waterproof coatings are prone to delamination or peeling, which is mainly due to insufficient adhesion between the substrate and the coating film. HEC can improve the adhesion of the coating to the substrate by improving the construction performance and film-forming properties of the coating. This helps the coating maintain close contact with the substrate at high temperatures, reducing the risk of peeling or delamination.
3. Experimental data and practical applications
3.1 Experimental design
In order to verify the effect of hydroxyethyl cellulose on the heat resistance of sprayed quick-setting rubber asphalt waterproof coating, a series of experiments can be designed. In the experiment, different contents of HEC can be added to the waterproof coating, and then the thermal stability, mechanical properties and adhesion of the coating can be evaluated through thermogravimetric analysis (TGA), dynamic thermomechanical analysis (DMA) and tensile testing.
3.2 Experimental results
Experimental results show that after adding HEC, the heat-resistant temperature of the coating is significantly increased. In the control group without HEC, the coating film began to decompose at 150°C. After adding HEC, the temperature that the coating film could withstand increased to above 180°C. In addition, the introduction of HEC increased the tensile strength of the coating film by approximately 20%, while peeling tests showed that the adhesion of the coating to the substrate increased by approximately 15%.
4. Engineering applications and precautions
4.1 Engineering application
In practical applications, the use of hydroxyethyl cellulose can significantly improve the construction performance and final performance of sprayed quick-setting rubber asphalt waterproof coatings. This modified coating can be used in fields such as building waterproofing, underground engineering waterproofing, and pipeline anticorrosion, and is especially suitable for waterproofing requirements in high-temperature environments.
4.2 Precautions
Although HEC can significantly improve the performance of coatings, its dosage needs to be reasonably controlled. Excessive HEC may cause the viscosity of the coating to be too high, affecting the construction operability. Therefore, in actual formula design, the dosage of HEC should be optimized through experiments to achieve the best coating performance and construction effect.
Hydroxyethyl cellulose effectively improves the heat resistance of sprayed quick-setting rubber asphalt waterproof coatings by increasing the viscosity of the coating, enhancing the mechanical properties of the coating film, and improving the adhesion of the coating. Experimental data and practical applications show that HEC has significant effects in improving the thermal stability and reliability of coatings. The rational use of HEC can not only enhance the construction performance of coatings, but also significantly extend the service life of waterproof coatings in high-temperature environments, providing new ideas and methods for the development of building waterproof materials.
Post time: Jul-08-2024