Application of HPMC in mortar and plaster

Hydroxypropyl methylcellulose (HPMC) is a non-ionic cellulose ether, which is widely used in dry-mixed materials such as building mortar and plaster as a key functional additive. Its main functions include:

Excellent water retention: HPMC can significantly improve the water retention capacity of mortar. After absorbing water and swelling, it forms a spatial network structure, which effectively locks in moisture, delays evaporation, and ensures that the cement is fully hydrated. This is especially important in high-temperature dry environments or on highly absorbent substrates, which can prevent the "burning slurry" phenomenon caused by excessive loss of moisture, reduce strength loss, decreased adhesion, cracking, hollowing and other risks.

Improving construction and processability: HPMC gives mortar good consistency and lubricity, improving its spreadability, ease of application and surface flatness. Its lubricating effect reduces the interfacial resistance between mortar and tools/substrate, making it easier to compact. For mechanical spraying applications, HPMC can optimize pumping performance and enhance material stability.

Enhanced adhesion and anti-sagging: HPMC enhances the adhesion between mortar and substrate after film formation, reducing shedding and hollowing. At the same time, it can significantly improve the thixotropy of mortar, so that it has sufficient structural strength to resist sagging in a static state (especially when constructed on a vertical surface), while maintaining good fluidity under construction disturbance.

Regulating open and adjustable time: HPMC can effectively extend the open time (the time window for maintaining adhesion) and adjustable time (the time allowed for position adjustment) of mortar, providing greater operational flexibility for construction and reducing errors.

Improved stability and environmental protection: HPMC increases the viscosity of the system, prevents the separation and sedimentation of dry-mixed mortar components, and ensures product uniformity and construction consistency. As a natural cellulose derivative, HPMC is environmentally friendly and compatible with a variety of systems such as cement-based and gypsum-based.

Conclusion:

Hydroxypropyl methylcellulose (HPMC) has become an indispensable core additive for modern high-performance mortars by improving water retention, workability, adhesion, anti-sagging, time adjustability and stability. It plays a key role in improving material quality, construction efficiency and ultimate durability, is in line with the development trend of green building materials, and has broad application prospects.