Although there are numerous formulations for creating dry and ready-mixed construction materials, all share a common set of critical properties, such as requiring a high degree of strength and workability while maintaining a good appearance. Many of these properties are achieved when formulations are made to optimize water retention, rheology, adhesion, and homogeneity.
METHOCEL™ hydroxypropyl methylcellulose (HPMC), or hypromellose, is the preferred ingredient to add to building and construction materials when performance and quality are paramount. METHOCEL™ is a nonionic cellulose ether made from cottonwood or cotton linters. It is highly retentive to water, controls the viscosity of solutions and slurries to tight specifications, increases adhesion and lubricity, and blends invisibly into many products used in the construction industry, such as those listed below.
- Gypsum and cement plasters
- Masonry mortars
- Grouts
- Tile and block adhesives
- Tape–joint compounds
Characteristics and Benefits of METHOCEL™ HPMC
Workability and Plasticity: The addition of METHOCEL™ significantly improves the workability of cement- and gypsum-based plasters, mortars, tile adhesives, and joint compounds by functioning as a thickener, lubricating agent, and water-retaining agent, making these products smoother and easier to spread. METHOCEL™ also functions as a set time retarder, meaning that open times are increased, providing a better window for workability. The result is a product with a more polished look, tighter adhesion to surfaces, and a smoother surface to the touch.
Water Retention and Strength: Plasters, mortars, and tile adhesives build strength through a gelation process from a hydration reaction that takes place during curing. In this reaction, water converts silicates in cement silicates and converts calcium sulfate hemihydrate in gypsum-based products into complex hydrates and calcium sulfate dihydrate, respectively. Both of these products increase strength as products cure. If water is lost due to evaporation or capillary action to surrounding materials, this reaction cannot be executed completely, and poor strength will be developed. METHOCEL™ plays an important role in increasing the water retention of building materials, making it such that water added into a mix is used to build bond strength and shear strength and is not lost due to evaporation or absorption. The water retention properties of METHOCEL™ typically improve with increasing viscosity.
Bonding: Adding METHOCEL™ can significantly improve the bonding of cement mortar, plaster, and adhesives, particularly by increasing the initial contact surface area. This is achieved because of the increased viscosity and adhesive properties METHOCEL™ provides, which ensure that the plaster, mortar, and adhesives applied to walls, bricks, or tiles do not sag or slide down after initial application. The amount of METHOCEL™ to add should be experimentally determined per product; too much will make the paste overly adhere to the construction tool.
Air-Entraining Agent: When METHOCEL™ is added to cementitious materials, many tiny bubbles form inside, resembling a honeycomb structure. These small bubbles can provide better cracking resistance by designating spaces for water to freeze in, which is safer for the material and improves freeze–thaw stability. Furthermore, the honeycomb structure blocks the capillary action generated after the original cement hardening and prevents water penetration, allowing the walls, the tiles, and the rest of the structure to be more waterproof. The air-entraining action also improves heat and sound insulation effects and decreases the bulk density of the product.
Recommended METHOCEL™ Cellulose Ether Grades for Building Materials
| Grade |
Typical Viscosity
(2% in water at 20°C, mPa·s) |
Applications |
| METHOCEL™ 228S |
5,000 |
Gypsum and cement plasters, masonry mortars, grouts, and tile and block adhesives |
| METHOCEL™ 254 |
32,000 |
Cement plasters, masonry mortars, grouts, and cement-based tile and block adhesives |
| METHOCEL™ J12MS |
10,000–16,500 |
Ready-mix tile adhesives and renders |
| METHOCEL™ J75MS |
60,000–90,000 |
Ready-mix tile adhesives and renders |
| METHOCEL™ 240S |
30,000–50,000 |
Tape–joint compounds |
Achieve the best results in your building materials with METHOCEL™ cellulose ethers.
Solutions for every building material application are now available in North America and EMEA!
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