Question 4 (Textile Engineering & Fibre Science)
The fibre that dissolved in 59% (w/w) sulfuric acid solution is
Answer / Solution
Frequently Asked Questions | FAQs
Does viscose dissolve in sulphuric acid?
Yes, viscose, which is a type of regenerated cellulose fiber, can be dissolved in sulfuric acid under certain conditions. The process of dissolving viscose in sulfuric acid is known as “viscose solution” or “viscose dope” preparation, which is a crucial step in the production of viscose rayon, a widely used textile fiber.
During the production of viscose rayon, cellulose from a natural source, such as wood pulp, is first treated with caustic soda (sodium hydroxide) to form alkali cellulose. The alkali cellulose is then treated with carbon disulfide to form cellulose xanthate, which is a soluble derivative of cellulose. The cellulose xanthate is dissolved in sulfuric acid to create a viscose solution or dope, which is a thick liquid with a yellowish color.
The viscose solution is then used to spin fibers through a spinneret into a coagulating bath, where the cellulose xanthate is regenerated into cellulose fibers through a process called coagulation. The coagulated cellulose fibers are then washed, neutralized, and further processed to create viscose rayon fibers.
It’s important to note that sulfuric acid is a hazardous and corrosive chemical, and the handling and disposal of viscose solution and other chemicals involved in the viscose rayon production process should be done with proper safety precautions and in compliance with environmental regulations.