What are the functions of HPMC?

Hydroxypropyl methylcellulose (HPMC) is a key ether additive in building materials. Based on its solubility characteristics, it is mainly divided into two types: cold-water-soluble and hot-melt, to meet the needs of different processes and products.

Cold-water-soluble HPMC is suitable for ready-to-use water-based systems, such as putty, mortar, liquid adhesives, coatings, and daily chemical products, and can be quickly dispersed and dissolved in cold water. Hot-melt HPMC is mainly used in dry powder building materials, such as putty powder and dry-mixed mortar. After being mixed with dry powder, it can function uniformly upon contact with water.

In hydraulic materials such as cement and gypsum, HPMC can significantly improve the following properties:

Water retention and setting regulation: Effectively improves the water retention of the system, extends the workable time and open time, slows down water evaporation, and promotes full hydration of cement.

Workability and stability: Gives the slurry good lubricity and plasticity, improves pumping and troweling efficiency; its suspending ability ensures uniform distribution of solid particles, preventing segregation and sedimentation.

Bonding and Crack Resistance: Enhances the bonding strength of materials such as tile adhesives and improves sag resistance; by introducing appropriate microbubbles, it improves mortar flexibility and reduces the risk of cracking.

Appearance and Durability: Helps form a smooth and uniform finish, improving the appearance quality and overall durability of the finished product.

In summary, HPMC, with its excellent water retention, thickening, bonding, and rheology control functions, is a key additive for improving the workability, mechanical strength, and final appearance of building materials.