Question

The major constituent of cotton fibre is

• A. hemicellulose
• B. cellulose
• C. lignin
• D. pectins

Hint:

Remember that cotton is essentially "nature's cellulose." Unlike wood or jute, it has very little lignin.

Answer 1

The Correct Option is B

Concept: Cotton is a natural seed fiber harvested from the cotton plant. In its raw state, it is considered the purest form of cellulose found in nature. To understand its behavior in textile processing, one must look at its chemical building blocks.
• Cellulose: A high molecular weight linear polymer that provides the structural strength and fibrous nature of the cotton boll.
• Non-cellulosic constituents: Natural cotton contains small percentages of impurities like proteins, fats, waxes, and pectins.

Step 1: Chemical Composition Analysis.
The chemical analysis of a typical mature cotton fiber shows that it is composed primarily of cellulose. The remaining parts consist of minor constituents like pectins, proteins, and waxes.

Step 2: Identifying the Major Component.
Since cellulose makes up the vast majority of the fiber's dry weight, it is the primary constituent that dictates the fiber's chemical and physical properties.