What is CMC
CMC stands for carboxymethyl cellulose, a cellulose derivative. Thus CMC is a biopolymer based on nature's most abundant raw material cellulose and can be described as polymer with carboxymethyl groups grafted onto a cellulosic backbone.
Chemically CMC is an anionic, linear molecule where some of the hydroxyl groups are replaced by carboxymethyl groups (-CH2-COONa). The amount of theses substituent groups determines the solubility and rheological behaviour.
In contrary to its base material cellulose, CMC is water soluble. Dissolved in aqueous solutions, CMC inspires versatile properties which provide already at low concentration rates cost effective solutions for a broad range of industries.
CMC as chemical is considered as harmless, being neither toxic nor hazardous.
From Cellulose to CMC
Cellulose is the most common and renewable biopolymer with a worldwide annual increment of approximately 500 - 1,000 billion tons.
The basic structure of cellulose within a plant is depicted on the left. When zooming into a plant cell, one sees with decreasing length scales:
- plant
- wood fibre
- macro fibrils
- micro fibrils
- cellulose molecules
Cellulose and CMC are chemically closely related, with cellulose being the backbone of the CMC molecule. CMC is technologically derived in a chemical modification process, via introduction of carboxymethyl groups.