Why Mercerizing is called a physiochemical Process?

What is Mercerizing?

Mercerizing: Mercerizing is a physico, chemical process where cotton treated 15-20% soda solution at a temperature of 20⁰-30⁰C

Mercerization Chemical reaction:

C₆H₇O₂(OH)₃ + NaOH →  C₆H₇O₂(OH)₂ (ONa) + H₂O

(Cellulose-I) (Alkali Cellulose)

↓

C₆H₇O₂(OH) + NaOH

(Cellulose-II)

Why Mercerizing is called a physiochemical Process?

Step-1: Cotton fibre has a kidney-shape in x-section with a lumen at the centre.

Step-2: Cellulose of the fibre begins to swell into aqueous solⁿ of sodium hydroxide.

step-3: Immediately the fibre becomes elliptical in X-section.

Step-4: On further swelling, the section pounds off.

Step-5: Fibel width increases at least 25-30%. & cellulose wall swells inwards until the lumen is eliminate’s -d.

Step-6: When the fibre is washed off, it begins to shrinkage of the cellulose.

Step-7: On drying, a further & final shrinkage occurs & the lumen does not recover.

Benifit of Mercerizing:

• Improved tensile strength.
• Improved absorbency
• Improved dye affinity
• Improved smoothness
• Improved lusture