What are the criteria for choosing the building additive hydroxypropyl methylcellulose HPMC ?

What is Hydroxypropyl Methylcellulose (HPMC)?

What is it: HPMC is a chemically modified cellulose polymer that is off-white in color and considered safe for human consumption. It is most commonly used as an alternative to gelatin and gluten in vegan-friendly products.

Common uses:

Alternative to Gelatin: It serves as an alternative to gelatin because of its vegetarian source and its physical similarities to gelatin. This is extremely useful if you need to make your own supplements since it can help vegetarians and those with dietary restrictions consume supplements and medications.

Alternative to Gluten: It is also a very good replacement for gluten in gluten-free food. In baking bread, it limits “both the diffusion and the loss of water from the bread crumb and the interactions between starch and protein macromolecules,” which results in softer gluten-free bread and reduces staleness during storage.

Other uses: It acts as a thickening agent, coating polymer, binder, and bioadhesive in pharmaceutical, food, and industrial manufacturing.

Application in Building Materials

Hydroxypropyl methyl cellulose products are widely used to improve the performance of hydraulic building materials, such as cement and plaster.

HPMC can enhance the plastic viscosity and cohesion of mortar, reducing the water migration and loss ability, and improving the water retention of mortar

In the building materials, the dosage of hydroxypropyl methyl cellulose is very small, only 0.1% to 1%. But its effects are great and can be used as plasticizers, water-retaining agents, air-entraining agents and retarders in coatings, gray paste, mortar and cement products to play the role of water retention or the adhesive force between the bases. In addition, hydroxypropyl methyl cellulose also meets the demands of environmental protection. In the dry-mixed mortar, it helps to avoid performance instability caused by the formation of mixture, pollution of the surrounding environment, poor construction conditions and low labor efficiency. Tile adhesives and the internal & external wall putty usually use adhesive before. However, from an environmental point of view, the application of cellulose ethers can be more preferable, such as HydroxyEthyl Cellulose and hydroxypropyl methyl cellulose.

The effects of adding cellulose ethers include: 1). improving the initial and final setting time of cement; 2). enhancing the strength of cement mortar to overcome limits; 3). improving the water-holding capacity of cement and gypsum; 4). reducing the compressive strength and shear strength of cement mortar; 5). improving the bonding performance of mortar.