Hydroxypropyl starch ether (HPS) and cellulose ether are two common construction chemical additives, widely used in building materials, such as mortar, putty powder, coatings, etc. Although they have similarities in some properties, there are significant differences in many aspects such as raw material sources, chemical structures, physical properties, application effects, and costs.
1. Raw material sources and chemical structure
Hydroxypropyl starch ether (HPS)
HPS is based on natural starch and obtained through etherification modification reaction. Its main raw materials are corn, wheat, potatoes and other natural plants. Starch molecules are composed of glucose units linked by α-1,4-glycosidic bonds and a small amount of α-1,6-glycosidic bonds. After hydroxypropylation, a hydrophilic hydroxypropyl group is introduced into the HPS molecular structure, giving it certain thickening, water retention and modification functions.
cellulose ether
Cellulose ethers are derived from natural cellulose, such as cotton or wood. Cellulose is composed of glucose units linked by β-1,4-glycosidic bonds. Common cellulose ethers include hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), hydroxyethyl cellulose (HEC), etc. These compounds introduce different substituents through etherification reactions and have higher chemical stability and physical properties.
2. Physical properties
Performance characteristics of HPS
Thickening: HPS has good thickening effect, but compared with cellulose ether, its thickening ability is slightly weaker.
Water retention: HPS has moderate water retention and is suitable for low to mid-range building materials.
Workability: HPS can improve the workability of mortar and reduce sagging during construction.
Temperature resistance: HPS is highly sensitive to temperature and is greatly affected by ambient temperature.
Performance characteristics of cellulose ethers
Thickening: Cellulose ether has a strong thickening effect and can significantly increase the viscosity of mortar or putty.
Water retention: Cellulose ether has excellent water retention properties, especially in high temperature environments, which can extend the opening time of the mortar and prevent excessive water loss.
Workability: Cellulose ether is excellent in improving workability and can effectively reduce problems such as cracking and powdering.
Temperature resistance: Cellulose ether has strong adaptability to temperature changes and relatively stable performance.
3. Application effects
Application effect of HPS
In dry mortar, HPS mainly plays the role of improving workability, improving water retention, and reducing delamination and segregation. It is economical and suitable for use in scenarios with high cost control requirements, such as ordinary interior wall putty powder, floor leveling mortar, etc.
Application effect of cellulose ether
Cellulose ethers are widely used in high-performance mortars, tile adhesives, gypsum-based materials and exterior wall insulation systems. Its superior thickening and water retention properties can significantly improve the bonding strength and anti-slip performance of the material, and is especially suitable for projects that have high requirements on construction performance and finished product quality.
4. Cost and environmental protection
cost:
HPS has a lower cost and is suitable for use in price-sensitive markets. Cellulose ethers are relatively expensive, but have excellent performance and are cost-effective in demanding construction projects.
Environmental protection:
Both are derived from natural materials and have good environmental properties. However, because fewer chemical reagents are consumed in the production process of HPS, its environmental burden may be lower.
5. Selection basis
Performance requirements: If you have high requirements for thickening and water retention properties, you should choose cellulose ether; for materials that are cost-sensitive but require certain improvements in workability, you can consider using HPS.
Usage scenarios: High-temperature construction, exterior wall insulation, tile adhesive and other scenarios that require high-performance support are more suitable for cellulose ether; for ordinary interior wall putty or basic mortar, HPS can provide economical and practical solutions.
Hydroxypropyl starch ether and cellulose ether each have their own advantages and they play different roles in building materials. The selection needs to be comprehensively considered based on the performance requirements, cost control, construction environment and other factors of the specific project to achieve the best use effect.
Post time: Nov-21-2024