High Water Retention Agent Construction Grade HPMC Used in Drymix MortarJune 7th 2023
Putty powder is a building material for decorating houses. It is used as an adhesive to improve the spreadability and prolong the operating time. It is used as a paste for tile, marble, and plastic decoration, as a paste enhancer, and can also reduce the amount of cement.
Putty cellulose mainly plays a role of water retention so that the slurry will not crack due to drying too fast after application, and enhance the strength after hardening.
Hydroxypropyl methylcellulose will prolong the setting time of putty and delay the kinetics of putty, which is beneficial to increase the operating time of fresh materials, improve the consistency of putty and the loss of putty over time, but it may also delay the construction progress . The viscosity of hydroxypropyl methyl cellulose mainly affects water retention and workability, and has almost no effect on the kinetics of putty. When its molecular parameters are different, the delay effect on putty is different. The retarding ability of HEC is usually stronger than that of HPMC and MC; the less the methoxy content of HPMC and HEMC or the less the content of hydroxyethoxy in HEC, the more obvious the hydration of cellulose putty, and the molecular weight and hydroxypropoxy in HPMC The influence of base content is lower; the smaller the DS, the more obvious the retardation effect of cellulose. Regardless of whether the solution is acidic, neutral, or alkaline, the cellulose performance of hydroxypropyl methylcellulose is very stable. Therefore, when cellulose is added to putty, the hydroxyl group on the cellulose ether structure and the oxygen atom on the ether bond are associated with water molecules. Synthesize hydrogen bonds to form a spatial network, turning free water into bound water, which has a good water retention effect, which can prevent the mortar from segregating and bleeding, but also prevent the water from evaporating too quickly or being absorbed by the substrate during the initial period of curing , So that the cement can be better hydrated, so that the bonding strength of the putty and the substrate can be improved.
Adding cellulose to the putty powder formula can increase the adhesion of the putty, avoid the phenomenon of cracks or powder removal caused by too fast loss of water, reduce the sag phenomenon in the construction, and make the construction smoother. The cellulose ether is mainly used in the putty.
It is used for water retention, adhesion and lubrication.
The hydroxypropyl methyl cellulose produced by cellulose can make the putty powder batch easy and convenient for construction. Putty powder is generally used with a viscosity of 80,000 to 100,000. Generally, the external wall putty is added in 3.5-5 kg, and the internal wall putty is about 3-4 kg. This is the added amount of hydroxypropyl methylcellulose of the general regular brand.