Question

In emulsion polymerization, the initiator is generally

• A. Soluble in water
• B. Soluble in monomer
• C. Insoluble in both
• D. Soluble in both

Hint:

Potassium persulfate is a commonly used water-soluble initiator in emulsion polymerization.

Answer 1

The Correct Option is A

Step 1: Understanding emulsion polymerization.
Emulsion polymerization is carried out in an aqueous medium where monomer droplets are dispersed in water with the help of emulsifiers. The reaction mainly occurs in micelles.
Step 2: Role of initiator.
The initiator used in emulsion polymerization must be soluble in water so that it can generate free radicals in the aqueous phase, which then enter the micelles to initiate polymerization.
Step 3: Analysis of options.
(A) Soluble in water: Correct — Common initiators like potassium persulfate are water soluble.
(B) Soluble in monomer: This is typical of solution or bulk polymerization.
(C) Insoluble in both: Cannot initiate polymerization effectively.
(D) Soluble in both: Not generally used in emulsion systems.
Step 4: Conclusion.
In emulsion polymerization, the initiator is generally water soluble, hence option (A) is correct.