Chemically speaking, what is cellulose, respectively, what is cellulose ether?

Cellulose is the basic material of natural substances such as wood, flax or cotton and consists of long, unbranched fiber molecules. A single ”cellulose fiber” can consist of up to 10000 individual anhydroglucose units. In cellulose, the individual fiber molecules are arranged in bundles and thus form so called micro fibrils which ultimately result in a “densely woven” net like structure of cellulose molecules. The strong cohesion between the individual cellulose fibers is due to the huge number of strong hydrogen bonds.

The chemical structure of cellulose ether molecules is quite similar to cellulose. During etherification the three free OH groups of a single anhydroglucose unit are (at least partially) substituted, meaning the strong cohesion between the original cellulose molecules is weakened and thus the cellulose becomes water soluble. SE Tylose uses various substances to etherify cellulose. The resulting product portfolio of SE Tylose comprises of the following cellulose ether types:

• Methylhydroxyethyl cellulose (MHEC), Tylose® MH
• Methylhydroxypropyl cellulose (MHPC), Tylose MO
• Hydroxyethyl cellulose (HEC), Tylose H

You will find more information about the chemical aspects here.

Beside the type of substitution (type of etherification agent used), the degree of substitution considerably influences the properties of Tylose and is characterized by two parameters:

• Average Degree of Substitution (DS)
  The DS indicates how many hydroxyl groups of an anhydroglucose unit are etherified on average. The DS can have values between 0 to 3 and indexing can specify which substituent the indication relates to.

Examples:   DS_ME (ME = Methyl)

• Molar Degree of Substitution (MS)
  During the hydroxyethylation or the hydroxypropylation, multi substitution results in the development of side chains. The MS quantifies the average number of hydroxyethyl or hydroxypropyl groups per anhydroglucose unit. The MS, in contrast to the DS, can have values of > 3. As with the DS, indexing can specify which substituent the indication relates to.

Examples:  MS_HE (HE = Hydroxyethyl)
                 MS_HP (HP = Hydroxypropyl)

 

 

Linus