hydroxypropyl methylcellulose HPMC in Plastering MortarFebruary 2nd 2023
Cellulose ether manufacturer-HEMC is better than HPMC?
HPMC and HEMC have similar roles in building materials.
It can be used as dispersant, water retaining agent, thickener and binder, etc. It is mainly used in the molding of cement mortar and gypsum products. Used in cement mortar to increase its cohesiveness, workability, reduce flocculation, improve viscosity and shrinkage, and have water retention, reduce water loss on the concrete surface, increase strength, prevent cracks and weathering of water-soluble salts, etc.
It is widely used in cement-based plasters, gypsum plasters, gypsum products, masonry mortars, board joint fillers, joint fillers, tile adhesives, and self-leveling floor materials.
In paint, it can be used in latex paint and water-soluble resin paint components as film-forming agent, thickener, emulsifier and stabilizer, so that the paint film has good wear resistance, leveling and adhesion, and improves Surface tension, stability to acids and bases, and compatibility to metallic pigments. Due to its good viscosity storage stability, it is especially suitable as a dispersant in emulsified paints. All in all, although it is used in a small amount in the system, it has a great effect and is widely used.
The gel temperature of cellulose ether determines its thermal stability in application. The gel temperature of HPMC is usually between 60°C and 75°C, depending on the model, group content, and different production processes of different manufacturers. Due to the characteristics of the HEMC group, it has a high gel temperature, usually above 80 ° C, so its stability under high temperature conditions is due to HPMC.
In practical application, in a very hot construction environment in summer, the water retention of HEMC in wet-mixed mortar with the same viscosity and dosage has a greater advantage than that of HPMC. Especially in high temperature environment, mortar will sometimes be constructed at high temperature, and cellulose ether with too low gel temperature will lose the original thickening and water retention properties of cellulose ether at high temperature, thereby accelerating the fixation of cement and mortar The hardening directly affects the construction and crack resistance.
Since there are more hydrophilic groups in the structure of HEMC itself, it has better hydrophilicity, and the water retention rate of HEMC in mortar is slightly higher than that of HPMC for products of the same viscosity at the same dosage. In addition, HEMC’s ability to resist vertical flow is relatively better. Therefore, the effect of HEMC applied to tile adhesives will be better.
However, HPMC is still the mainstream cellulose ether in the construction industry in most countries. Because of its wide variety and low price, it can be freely selected in terms of overall cost. High-quality HPMC is not inferior to HEMC.
SLEOCHEM produces and sells cellulose ether products, including different grades of HPMC and HEMC. It can meet the needs of different usage environments, and the feedback effect is good. Looking forward to your consultation.