Question

In wet spinning of acrylic fibres

• A. Two-way mass transfer is involved
• B. One-way mass transfer is involved
• C. Coagulation bath having spinneret contains only solvent
• D. Coagulation bath having spinneret contains both solvent and non-solvent

Hint:

In wet spinning, always remember that controlled coagulation requires both diffusion directions (two-way transfer) and a mixed bath of solvent and non-solvent.

Answer 1

The Correct Option is A

In wet spinning, the polymer solution is extruded through a spinneret into a coagulation bath. During this process, there is a simultaneous outward diffusion of solvent from the polymer jet and an inward diffusion of non-solvent from the coagulation bath. This clearly indicates a two-way mass transfer. Hence, option (A) is correct.
Additionally, the coagulation bath must contain both solvent and non-solvent in order to maintain controlled precipitation of the polymer. If only solvent were present, no coagulation would occur; if only non-solvent were present, coagulation would be too abrupt. Thus, option (D) is correct.
Therefore, the correct answers are \fbox{(A) and (D)}.