Pectin is an acidic polysaccharide in plants, which is slightly acidic and easily soluble in water. It can be separated in industry, and its molecular weight is about 51300,000. Plant wax, wax quilt is usually attached to the surface of many plants (monocotyledons have more and thicker waxy layers), and its chemical composition is fatty compounds of higher fatty acids and higher monohydric alcohols, which is a high molecular weight thermoplastic solid.

The main component of cotton fiber is cellulose. Besides cellulose, cotton fiber also contains pectin, wax and protein. Its composition is as follows: cellulose 94%, protein 1.3%, pectin 1.2%, wax 0.6%, ash 1.2%, sugar 0.3%, pigment and others 65438.