The Importance of Water Retention of HPMC
April 24th 2024
The construction industry has experienced massive growth in incorporating new materials to enhance the output and overall performance of construction products. Among such trendy innovations is the gypsum plaster.
However, one of the ingredients that serve as the gypsum plaster’s bedrock, particularly in stability and thickening property, is cellulose.
In this article, we’ll briefly examine the roles of Hydroxypropyl Methyl Cellulose in the production of gypsum plaster.
Before we dive in, let’s quickly integrate you with gypsum plaster and the characteristics of HPMC.
What is Gypsum Plasters?
Widely known as hydrous calcium sulfate among chemists, gypsum itself is a water-soluble naturally occurring mineral. It exists freely in nature as crystals and can be located among layers of limestone and shale.
On the other hand, gypsum plaster is produced by heating gypsum at a very minimal temperature to achieve evaporation. The dehydrated gypsum known as Plaster of Paris (POP) is pulverized and heated at about 150℃. The dry POP powder hardens when you add water to form gypsum plaster. The concentration can be applied over concrete, brick, or block to further strengthen it.
Characteristics of Cellulose（HPMC）
HPMC cellulose exists as white, non-ionic cellulose ether. In its powdery form, it’s odorless and tasteless. It’s soluble in water and other organic content such as ethanol, propanol, and dichloroethane. However, it is insoluble in acetone, diethyl ether, and anhydrous alcohol.
When in an aqueous solution, HPMC offers high stability, transparency, and surface activity. Heating makes the Hydroxypropyl Methyl Cellulose precipitate for gels due to its thermal gelation properties.
Here are some other features of Hydroxypropyl Methyl Cellulose:
How does cellulose work in gypsum products?
High water retention
Cellulose has a high water-holding capacity. This attribute makes it useful to improve resistance, prevent cracking, and enhance gypsum plaster’s overall appearance. It also boosts surface uniformity, lubrication, and adhesion when applied to gypsum plaster in putty and other construction works.
Thickening property
HPMC is the right material for you if you want to increase the tensile strength of gypsum plaster and other construction material. It acts as an interface agent. That is, it improves gypsum plaster flexural strength and increases bonding strength.
Highly stable
HPMC’s outstanding film-forming properties and high resistance to degrading enzymes help stabilize gypsum plaster pH and enhance its salt discharge performance.
Others include dispersibility, constructability, and adhesive strength. Also, HPMC has effects on the setting time, pumpability, and workability of gypsum plaster composition. Overall, it enhances construction efficiency and guides against weathering after exposure of building surfaces to water-soluble salts.
All these make HPMC an integral part of the gypsum plaster every construction worker must-have.
Tags:
