In the formulations of building materials, the dosage of cellulose ether is only 0.1% to 1%. But it plays an irreplaceable role. Various applications of cellulose ether in building materials will be introduced as follows.
1. Latex and Latex Building Materials
Such cellulose derivatives as MC, CMC, HEC and HPMC can be used in the emulsion and latex paints. Their main function is thickening, to make the paint achieve the desired storage and viscosity for construction, without severe delamination during storage or dripping and sagging phenomena during use. Due to the strong water absorption capability of these cellulose derivatives, when added to the emulsion, they can immediately absorb a large amount of water, make the volume of themselves substantially expand, significantly increase the viscosity of the latex and thus achieve thickening purposes. However, the addition of such polymers can reduce the water resistance of coating films, so the dosage should be minimized as possible under the premise of reaching the required viscosity of the emulsion and latex paints, that is, try to use cellulose ethers with large molecular weight and high viscosity as possible.
2. Thermal Insulation Surface Mortar for Exterior Walls
Improvement of living standards requires that modern buildings should have good insulation properties. The government has also put forward the corresponding requirements for energy-saving buildings. This promotes the subject of wall insulation to be urgently on the agenda. Now what is the most used exterior insulation technology is sticking a layer of foam polystyrene board on the exterior wall surface first and then coating with a layer of surface mortar on outside it. But the surface of polystyrene board is different from ordinary plaster surface, and not easy to bond together with the mortar, However, the addition of water-soluble cellulose ethers in the mortar can not only increase the binding force between the mortar and the polystyrene board, but also can improve the workability and water-holding capacity of the mortar and make it not easy to crack.
3. Cement Mortar for Self-Leveling Floor
Self leveling is a very advanced floor construction technique. Since the whole ground is naturally leveled with slight interference of construction personnel, flatness and construction speed are greatly enhanced compared with the previous manual smoothing processes. The rise of self-leveling floor in China should be credited to the foreign building materials business and chemical company. The application of cellulose ether in dry mix mortar for self-leveling floor has mainly used its excellent water-holding properties. Since self leveling requires the well stirred mortar automatically leveling on the ground, the use of water materials is relatively large. Without the addition of cellulose ether, the ground surface after pouring will bleed water very severely, lead to low strength of the ground surface after drying and large shrinkage, and thus will be apt to dusting and cracks. The domestic industry is generally optimistic about this technique. With the continuous success of development of the mortar for self-leveling floor, the demand for the HPMC product will also increase dramatically.