Cellulose ether products are widely used to improve the performance of hydraulic building materials, such as gypsum and cement. In gypsum and cement-based mortars, it improves water retention, prolongs correction and open times, and reduces sagging.
1. Water retention
Cellulose ether prevents moisture from penetrating into the wall. An appropriate amount of water stays in the mortar, so that the gypsum and cement have a longer time to hydrate. The water retention is directly proportional to the viscosity of the cellulose ether solution in the mortar. The higher the viscosity, the better the water retention. Once the moisture factor increases, the water retention decreases. Because for the same amount of cellulose ether solution, an increase in water means a decrease in viscosity. The improvement of water retention will lead to the extension of the curing time of the mortar being constructed.
2. Reduce viscosity and improve workability
The lower the viscosity of the cellulose ether used, the lower the viscosity of the mortar and thus better workability. However, low viscosity cellulose ether has a higher dosage due to its low water retention.
3. Anti-sagging
A good sag-resistant mortar means that the mortar applied in thick layers has no danger of sagging or running downwards. Sag resistance can be improved by cellulose. Cellulose ether can provide better sag resistance of mortar.
4. Bubble content
High air bubble content results in better mortar yield and workability, reducing crack formation. It also lowers the intensity value, resulting in a “liquefaction” phenomenon. Air bubble content usually depends on stirring time.