Home page

Differences in the application of pregelatinized starch, carboxymethyl starch, and carboxymethyl cellulose in science and technology

Release time:

2023-10-11

Source:

reticulation

Pregelatinized starch is a kind of physically modified starch that is pre-gelatinized and then quickly dried. It can absorb water and swell into paste in cold water. Commonly used raw materials include corn starch and tapioca starch. The extrusion drying method is mostly used in the process, and there are also production processes such as drum drying and spray drying.

Sodium carboxymethyl cellulose

Sodium carboxymethylcellulose is an anionic polymer compound usually produced by the reaction of natural cellulose with caustic alkali and monochloroacetic acid, with a molecular weight ranging from several thousand to one million. Also known as (CMC-Na), it is an organic substance, a carboxymethylated derivative of cellulose, and the main ionic cellulose glue.

Appearance is white fibrous or granular powder, odorless, tasteless, hygroscopic, easily dispersed in water to form a transparent colloidal solution.

The differences and applications of the three types

"The chemical composition is different. Sodium carboxymethyl cellulose is made from refined cotton, or it is a water-soluble cellulose ether made from alkalization and etherification of cellulose. It has high viscosity and purity.

Sodium carboxymethyl starch is made from corn starch and its cost is lower than cellulose.

Pregelatinized starch is neutral and cms is alkaline.

Application in carburizer

The carburizing agent is generally made of natural graphite powder, artificial graphite powder, etc., which can be extruded, or rolled into balls, and then dried in the air.

Manufacturers who produce carburizers generally require that the binder be a pure organic binder, because in steelmaking or ironmaking, the price of carburizers is determined based on the fixed carbon content, and the higher the fixed carbon content, the better the product quality. . Therefore, it is required that the adhesive must be a pure organic adhesive that does not increase ash content, does not reduce fixed carbon, does not contain sulfur, phosphorus, etc., and has high strength and high temperature resistance. Therefore, among purely organic adhesives, those with starch as the main raw material are cost-effective adhesives.

Starch-based adhesives include: pregelatinized starch, sodium carboxymethyl starch, dextrin, etc. However, the three raw materials have their own merits. Pregelatinized starch has low viscosity, but high strength and stable quality. Starch-grade cellulose is manufactured using chemical methods, and the product is unstable, has high viscosity, and low bonding strength and dry strength. Dextrin has high viscosity, but its strength is relatively low. Therefore, in summary, Duan Jianjie's pregelatinized starch is the adhesive chosen by graphite carburizer manufacturers.