Question

The acrylic fiber is called artificial wool due to \(\underline{\hspace{2cm}}\) formed on removal of solvent during manufacturing.

• A. Twist
• B. Serrations
• C. Voids
• D. Faults

Hint:

The "secret" to acrylic's warmth is trapped air. This air is trapped in microscopic voids or pores created when the solvent is removed during the spinning process. More trapped air means better insulation.

Answer 1

The Correct Option is C

Step 1: Understand the property being explained. Acrylic is called "artificial wool" because it is bulky, lightweight, and has good warmth/insulation properties, similar to wool. 
 

Step 2: Analyze the manufacturing process of acrylic. Acrylic is typically wet or dry spun. During these processes, the polymer is dissolved in a solvent, extruded, and then the solvent is removed. When the solvent is removed rapidly from the fiber, it can leave behind microscopic, empty spaces or pores within the fiber structure. 
 

Step 3: Relate these structural features to the wool-like properties. These microscopic voids trap air inside the fiber. Trapped air is an excellent thermal insulator. This trapped air gives the acrylic fiber its low density (making it lightweight), bulkiness, and excellent insulation (warmth), which are the key characteristics that make it resemble wool. 

Conclusion: The formation of voids during solvent removal is responsible for the wool-like properties of acrylic fiber.