Starch ethers for building applications

Starch ethers can come from many sources, but Avebe’s starch ethers are derived from natural starch in potatoes, a renewable crop – so there’s no deforestation or other environmental damage in the production chain. Furthermore, the potatoes used aren’t for human consumption, so there’s no impact on the food supply.

As organic products derived from renewable sources, starch ethers are often a greener choice than synthetic ethers (which do not have sustainably source materials) or cellulose ethers (which often contribute to deforestation). Avebe’s starch ethers, derived from potato starch, are both renewable and low-impact with a transparent value chain.

Both starch and cellulose are organic compounds called polysaccharides, and when turned into ethers their main property is water retention. But since their molecular structures once etherified are different, the compounds have different properties – so mixing the two can give a wider range of advantages, from viscosity to workability, that each compound is less effective for when used alone.

While starch ethers can replace cellulose ethers in some applications, it’s often more advantageous for the two to work together. In short, a starch ether and a cellulose ether have different functions, but they work synergistically together to impart very beneficial improvements to a dry mortar formulation.
The primary function of a cellulose ether is to help retain water in a formulation to support complete of the primary binder (cement or gypsum). A starch ether’s main function is to improve workability, reduce slip and sag, support water retention, reduce stickiness and support with open times. Adding small volumes of starch ethers lets producers control rheology (the “feel” of a product) with high precision – for example, making a mixture more workable and pumpable without making it thicker.
Starch ethers impart a buttery feel that is much appreciated by professionals.

Starch is a polysaccharide: basically, a sequence of polymer molecules “glued together” by their carbon atoms. Also in these molecules are oxygen atoms, which bind to hydrogen to form one of the simplest structures in organic chemistry, called a hydroxyl group. Ethers are also molecular structures called alkyl or aryl groups, which bind to oxygen atoms in the starch to form a starch ether.

The structure of a starch ether is “hydrophilic”, meaning it attracts and retains water. This is how starch ethers create benefits across a range of industrial products: keeping water in a compound lets manufacturers control how a mixture thickens, emulsifies, and stays stable in a range of conditions.

Starch ethers are flexible and available in a range of formulations suited to many use cases. Dry-mix materials are used all over the world in many different conditions; adding starch ethers to a dry-mix mortar product lets producers control a mixture’s smoothing ability, reducing the tendency of adhesives to sag and slip, make it easier to work with over large or difficult surface areas, and extend open time.

Starch ethers can be added at source in the factory or added to ready-to-use products on construction sites to improve their performance characteristics. A small dosage into a dry mortar formulation results in a significant performance benefit.

Professional opinions about starch ethers are positive and widespread. Tilers value the way they reduce sag or slip; plasterers like the improved workability and open time they add to dry mix mortar; large construction sites gain advantage from easier pumpability that makes projects move faster with less rework. And with starch ether additives for ready-for-use available, building trade professionals can also “dial in” the performance characteristics – such as thickness and smoothness – that are right for their job.

Starch ethers bring benefits at low concentrations. Avebe Starch ethers are highly efficient additives and deliver significant formulation benefits at very low doses. Dosages vary according to the primary binder used, the formulation and the end application. Typical starting dosage is approximately 0.1% of cellulose ether.