The role and application of HPMC in building mortar

1. Introduction to HPMC

Hydroxypropyl Methylcellulose (HPMC) is a non-ionic cellulose ether widely used in building materials, coatings, medicine, food and other industries. In the construction field, HPMC is mainly used in cement mortar, gypsum-based products, putty powder and tile adhesive to improve their construction performance and durability.

2. The role of HPMC in building mortar

(1) Improving water retention

HPMC has excellent water retention properties, which can reduce the rapid evaporation of water in the mortar, prevent excessive water absorption of the base layer, and reduce the cracking and shrinkage problems caused by water loss. It is particularly suitable for construction in high temperature and dry environments.

(2) Improving construction performance

HPMC can significantly enhance the lubricity and operability of the mortar, making it easier to spread and level, reducing the difficulty of construction. At the same time, it can also improve the adhesion of the mortar, reduce falling phenomena, and improve construction efficiency.

(3) Enhanced bonding strength

In tile adhesive and plaster mortar, HPMC can improve the bonding strength of mortar to base materials, reduce shedding and cracking problems, and ensure construction quality.

(4) Improved anti-sagging performance

During wall or ceiling construction, mortar is often prone to sliding down due to its own weight. HPMC has an excellent thickening effect and can effectively improve the anti-sagging ability of mortar and ensure construction accuracy.

(5) Optimize the plasticity and anti-sagging properties of mortar

HPMC can adjust the consistency and rheology of mortar so that it maintains appropriate plasticity during construction, reduces segregation and water seepage, and improves construction quality.

3. Application of HPMC in different types of mortars

(1) Masonry mortar

In masonry mortar, HPMC provides good water retention, prevents bricks from absorbing water too quickly, improves masonry strength, ensures that mortar is evenly distributed between bricks and stones, and enhances the integrity of the masonry structure.

(2) Plastering mortar

HPMC can improve the construction and adhesion of plastering mortar, making it easier to apply, and reduce cracking and hollowing, improving the smoothness and durability of the wall surface.

(3) Self-leveling mortar

In self-leveling mortar, HPMC is mainly used as a thickener and dispersant to control the fluidity of mortar, prevent precipitation, and improve construction uniformity and flatness.

(4) Tile adhesive

HPMC can improve the adhesion of tile adhesive, extend its open time, enhance wet viscosity, reduce brick falling during construction, and improve paving quality.

4. Key parameters when selecting HPMC

The following key indicators should be paid attention to when selecting suitable HPMC products:

Viscosity: The higher the viscosity, the stronger the thickening and water retention ability, but it may affect the construction fluidity. Generally speaking, the viscosity range of HPMC for construction mortar is between 400-75,000 mPa·s.

Degree of substitution (DS): The degree of substitution affects solubility and stability. The appropriate degree of substitution can improve the performance of mortar.

Particle size: The smaller the particle size, the faster it dissolves and the better the dispersion. It is generally recommended to use HPMC with a particle size of 80-100 mesh.

Moisture content: A lower moisture content helps to improve the storage stability of the product.

HPMC is widely used and indispensable in building mortar. It can significantly improve the water retention, workability, adhesion and anti-sagging properties of the mortar, and improve the quality of the mortar and construction efficiency. When choosing HPMC, you should choose the appropriate product according to the specific construction needs to ensure the best construction effect.