Mechanism of action of hydroxypropyl methylcellulose ether (HPMC) in mortar

Shijiazhuang Qingquan Cellulose Co., Ltd.specializes in the research, development, production, and sales of building additives. Hydroxypropyl methylcellulose ether (HPMC), as an important cellulose ether admixture in dry-mix mortar, plays a multifaceted role. The most important functions of HPMC in cement mortar are water retention and thickening. Additionally, due to its interaction with the cement system, it also plays a supporting role in air entrainment, retarding setting, and improving tensile bond strength. The most important property of HPMC in mortar is its water retention. As a cellulose ether admixture, HPMC can be used in almost all mortar products, primarily utilizing its water retention properties. Generally, the water retention of HPMC is related to its viscosity, degree of substitution, and particle size. As a thickener, the thickening effect of HPMC is related to its degree of substitution, particle size, viscosity, and degree of modification. Generally, the higher the degree of substitution and viscosity of the cellulose ether, and the smaller the particle size, the more significant the thickening effect.

In hydroxypropyl methylcellulose ether (HPMC), the introduction of methoxy groups lowers the surface energy of the aqueous solution containing hydroxypropyl methylcellulose, thus enabling hydroxypropyl methylcellulose to entrain air in cement mortar. Introducing appropriate air bubbles into the mortar improves its workability due to the "ball-bearing effect," and also increases mortar yield. However, the amount of air entrainment needs to be controlled; excessive air entrainment negatively impacts mortar strength.

Hydroxypropyl methylcellulose delays the cement setting process, thus slowing down the hardening process and extending the open time of the mortar. However, this effect is detrimental to mortar in colder regions. As a long-chain polymer, hydroxypropyl methylcellulose, when added to the cement system, can improve adhesion to the substrate while maintaining sufficient moisture in the mortar.

In summary, the main properties of hydroxypropyl methylcellulose ether (HPMC) in mortar include: water retention, thickening, extended setting time, air entrainment, and improved tensile bond strength. Shijiazhuang Qingquan Cellulose specializes in the production and sales of hydroxypropyl methylcellulose (HPMC). The company offers a complete range of cellulose products, with corresponding models available for different types of mortar. The products are cost-effective, and the company's strong professional technology brings benefits and convenience to mortar companies.