Question

Amongst the following, the correct statement(s) for regenerated cellulosic fibres is/are:

• A. Degree of polymerization of Lyocell is higher than that of viscose
• B. Degree of crystallinity of Lyocell is lower than that of viscose
• C. Spinning dope of Lyocell is an aqueous solution
• D. Wet strength of Lyocell is lower than that of viscose

Hint:

Lyocell is known for its environmentally friendly production process and higher strength in both wet and dry conditions compared to viscose.

Answer 1

The Correct Option is A, C

Step 1: Degree of polymerization.
The degree of polymerization of Lyocell is higher than that of viscose due to the more controlled and less degraded process used for spinning Lyocell fibers. This results in a higher molecular weight and better fiber strength.

Step 2: Degree of crystallinity.
The degree of crystallinity in Lyocell is generally higher than in viscose, not lower. Viscose fibers have a more amorphous structure, whereas Lyocell fibers have a more crystalline structure.

Step 3: Spinning dope.
Lyocell is produced by dissolving cellulose in an aqueous solution of N-methylmorpholine N-oxide (NMMO), which makes the spinning dope of Lyocell an aqueous solution.

Step 4: Wet strength.
Lyocell fibers generally have a higher wet strength compared to viscose fibers. The statement that the wet strength of Lyocell is lower than that of viscose is false.