Cellulose ether, especially hydroxypropyl methylcellulose ether (HPMC) is an important component in commercial mortar. For cellulose ether, its viscosity is an important indicator that mortar manufacturers pay attention to, and high viscosity has almost become the basic demand of the mortar industry. For domestic cellulose ether manufacturers, due to the influence of their technology, process and equipment, it is difficult to guarantee the high viscosity of cellulose ether products for a long time.
Since domestic cellulose ether entered the mortar industry in 2003, the viscosity of cellulose ether, especially hydroxypropyl methyl cellulose ether (HPMC), has become an unavoidable problem. On the one hand, from the beginning of domestic cellulose ether entering the mortar industry, cannot compete with imported products in terms of application performance understanding, product stability, and product additional functions. Apart from price, the only bright spot that can be advertised is high viscosity; on the other hand, domestic cellulose mainly uses refined cotton as raw materials. Compared with foreign products that use wood pulp as raw material, it is easy to achieve relatively high viscosity. Although from the perspective of mortar application technology, high viscosity does not have much positive help for the application, but this concept advocated by domestic cellulose ether manufacturers has left a deep imprint on the application technology of dry powder mortar. Change. The viscosity of cellulose ether has become the first indicator that mortar enterprises pay attention to, and the need for high viscosity has become the basic requirement of domestic mortar enterprises. However, due to the inherent deficiencies in production equipment, process flow, and production technology, it is difficult for domestic cellulose ether companies to ensure long-term stable production of high-viscosity products, while most mortar manufacturers only want high-viscosity products. Under the current situation, cellulose ether manufacturers do everything possible to increase the viscosity of the product, so “viscosity enhancer” or “viscosity enhancer” came into being. “Viscosity enhancer” or “viscosity enhancer” is actually a crosslinking agent. In principle, the linear molecular structure of cellulose ether is crosslinked into a network, which increases the steric hindrance in the cellulose ether aqueous solution. As a result, the cellulose ether aqueous solution shows a high viscosity when tested, but it is actually a pseudo-viscosity.
Cellulose ether is used in mortar products as a water-retaining agent, thickener and binder, and has an important impact on the operability, wet viscosity, operating time and construction mode of the mortar system. These functions are mainly accomplished through the formation of hydrogen bonds between cellulose ether molecules and water molecules and the entanglement of cellulose ether molecules. The addition of the viscosity-enhancing agent actually takes up part of the hydrogen bonds on the cellulose ether molecular chain and the entanglement of cellulose ether molecules is weakened, and the water retention and wetting ability of cellulose ether are weakened. Most of the mortar manufacturers do not feel this point. On the one hand, the domestic mortar products are relatively rough and have not yet reached the stage of paying close attention to the operability. On the other hand, the viscosity we choose is much higher than the technically required viscosity, this part also compensates for the loss of water retention capacity, but there is obvious damage in wetting performance.
The cellulose ether containing viscosifier in the production process has an impact on the final performance of the mortar. This paper has verified the application of cellulose products under normal process conditions and cellulose ether products with viscosifiers in the production process to ceramic tiles. In glue, the difference in tensile adhesive strength after curing under different conditions.
Post time: Mar-07-2023