Question

The reactivity ratios of monomer 1 and monomer 2 are r₁ and r₂. If r₁ = r₂ = 0

• A. Alternating copolymer will form
• B. Block copolymer will form
• C. Random copolymer will form
• D. Homopolymer will form

Hint:

Zero reactivity ratios are a hallmark of perfectly alternating copolymerization.

Answer 1

The Correct Option is A

Step 1: Understanding reactivity ratios.
Reactivity ratios indicate the preference of a growing polymer radical to add the same or a different monomer. They play a crucial role in determining the copolymer microstructure.
Step 2: Meaning of r₁ = r₂ = 0.
When both reactivity ratios are zero, a radical of monomer 1 cannot add monomer 1, and a radical of monomer 2 cannot add monomer 2. Each radical can only add the opposite monomer.
Step 3: Analysis of options.
(A) Alternating copolymer will form: Correct — Strict alternation of monomers occurs.
(B) Block copolymer will form: Requires sequential polymerization, not governed by r values.
(C) Random copolymer will form: Occurs when r₁ and r₂ are close to 1.
(D) Homopolymer will form: Requires r values much greater than 1.
Step 4: Conclusion.
If r₁ = r₂ = 0, an alternating copolymer is formed, making option (A) correct.