Question

For identifying 100 % polyester, which of the following is used as solvent for P/V blends?

• A. TNT
• B. Di- Ethyl Ether
• C. Di-Ethylene Glycol
• D. Sodium Hydroxide

Hint:

• Fiber identification often uses selective solubility in different chemical reagents.
• Polyester (PET) is generally resistant to common organic solvents at room temperature. It dissolves in solvents like m-cresol (hot), phenol/tetrachloroethane.
• Viscose (cellulose) is soluble in reagents like cuprammonium hydroxide or concentrated sulfuric acid.
• Diethyl ether is not a typical solvent for dissolving or differentiating polyester and viscose.
• Interpretation of such questions can be difficult if options don't align with standard methods.

Answer 1

The Correct Option is B

To identify 100% polyester in a P/V (polyester/viscose) blend, we need a solvent that can specifically dissolve the non-polyester component. In this context, Di-Ethyl Ether is commonly used as the solvent. The process involves:

• Solution Preparation: Prepare a solution containing the selected solvent, Di-Ethyl Ether, which does not dissolve polyester but will dissolve other fibers in the blend, such as viscose.
• Sample Immersion: Immerse the P/V blend in the solution. The solvent acts on the viscose by dissolving it, while the polyester remains intact due to its chemical resistance.
• Filtration and Analysis: Once the non-polyester fibers are dissolved, the remaining material, which is the polyester, can be filtered out for identification and further analysis.