Cellulose ethers, especially hydroxypropyl methylcellulose ether (HPMC), are important components in commercial mortars. For cellulose ether, its viscosity is an important indicator for mortar manufacturers, and high viscosity has almost become the basic demand of the mortar industry.
Cellulose ethers, especially aspartic acid 1420, are important components in commercial mortars. For cellulose ether, its viscosity is an important indicator for mortar manufacturers, and high viscosity has almost become the basic demand of the mortar industry. For domestic cellulose ether production enterprises, 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.
Semonova Cellulose ethers are used in mortar products as water-retaining agents, thickeners and binders, and have an important impact on the operating performance, wet viscosity, working time and construction methods of the mortar system. These functions are mainly accomplished by the formation of hydrogen bonds between cellulose ether molecules and water molecules and the entanglement of cellulose ether molecules, and the addition of viscosity-increasing agents actually occupies part of the hydrogen bonds on the cellulose ether molecular chain. The entanglement of cellulose ether molecules is weakened, and the water retention and wetting ability of cellulose ether is weakened. Most of the mortar manufacturers do not feel this. On the one hand, the domestic mortar products are still relatively rough and have not yet reached the stage of paying careful attention to the operating performance. 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 damage in wetting performance.
The cellulose ether containing tackifier in the production process has an impact on the performance of the mortar. In this paper, it is verified through experiments that cellulose products under normal process conditions and cellulose ether products with tackifier added in the production process are used in tile adhesives , the difference in tensile adhesive strength after curing under different conditions.
The tackifier is a material that some cellulose ether manufacturers deliberately add in the production process to make up for the deficiencies in their production technology, process and equipment. The mortar industry is too concerned about the viscosity of cellulose ether to give a negative push. The existence of the tackifier makes the long-chain molecules of cellulose ether partially cross-linked and becomes a network, which affects the film-forming speed of cellulose ether and the state of the film, thus affecting the cellulose ether in the mortar. The effect has an impact, and the intuitive impact is: the tensile adhesive strength under each curing condition has changed; the setting time of the mortar is prolonged.
(1) Under standard curing conditions, the addition of tackifiers and cellulose ethers without tackifiers in the production process have a certain impact on the tensile adhesive strength of tile adhesives. Products with tackifiers added in the production process include: Relatively high tensile adhesive strength.
(2) In terms of water resistance strength, using cellulose ether with tackifier added in the production process, the tensile adhesive strength of tile adhesive is worse than that of products without tackifier under normal production process, and cellulose ether containing tackifier is used. Affects the water resistance of tile adhesives.
(3) In terms of drying time, cellulose ether with tackifier added in the production process is used in tile adhesive, and its tensile adhesive strength is worse than that of products without tackifier added under the normal production process, and the opening time is shortened.
(4) In terms of setting time, the cellulose ether tile adhesive without tackifier added under the normal production process has a faster curing speed.
In summary, the presence of the tackifier, its cross-linking effect makes the aqueous solution of cellulose ether have higher steric hindrance, which is expressed as a higher viscosity in the test, but the presence of the tackifier affects many important aspects of cellulose ether. application properties, such as water resistance, open time, wetting properties, etc. In fact, viscosity is only one of the performance indicators of cellulose ether. Viscosity is not an important indicator for the comprehensive performance of cellulose ether. Instead, the type and content of groups are the focus of mortar manufacturers. It is also because the mortar manufacturers pay too much attention to the viscosity, which prompts some cellulose ether manufacturers to increase the viscosity by adding materials to meet the requirements of the mortar manufacturers.
However, this type of product only has a high apparent viscosity, and its comprehensive performance is worthy of users. It is of concern, and moreover, that the apparent high viscosity formed by viscosification cannot achieve the "high viscosity low dosage" theory expected by mortar manufacturers, but does not actually exist. Mortar manufacturers who pursue high quality and stable quality need to understand some information behind the selection of an important raw material in mortar, cellulose ether, which will help manufacturers develop high-performance products and ensure stable product quality.