Which of the following sets contain only copolymers?

Options

A. Melamine, Bakelite, PVC
B. Buna-N, Nylon-6, Polythene
C. Buna-S, Nylon-6, 6, Glyptal
D. Neoprene, Styron, Polyisoprene

Answer

To solve the question of identifying which of the following sets contain only copolymers, we need to understand the definition of copolymers and analyze each option provided. Here’s a step-by-step solution:

### Step 1: Understand the Definition of Copolymers
A copolymer is a polymer that is made from two or more different types of monomeric units. This means that in the structure of a copolymer, there are at least two different kinds of repeating units.

### Step 2: Analyze Each Option
We will evaluate each option to determine whether it consists solely of copolymers.

1. **Melamine**: This is a polymer formed from a single type of monomer, melamine itself, and formaldehyde. **Not a copolymer.**

2. **Bakelite**: This is made from phenol and formaldehyde. It consists of two different monomers. **This is a copolymer.**

3. **PVC (Polyvinyl Chloride)**: This is made from vinyl chloride, which is a single type of monomer. **Not a copolymer.**

4. **Buna-N**: This is made from 1,3-butadiene and acrylonitrile. It consists of two different monomers. **This is a copolymer.**

5. **Nylon 6**: This is made from caprolactam, which is a single type of monomer. **Not a copolymer.**

6. **Polyethylene**: This is made from ethylene, which is a single type of monomer. **Not a copolymer.**

7. **Buna-S**: This is made from styrene and 1,3-butadiene. It consists of two different monomers. **This is a copolymer.**

8. **Nylon 6-6**: This is made from adipic acid and hexamethylene diamine. It consists of two different monomers. **This is a copolymer.**

9. **Glyptal**: This is made from ethylene glycol and phthalic acid. It consists of two different monomers. **This is a copolymer.**

10. **Neoprene**: This is made from chloroprene, which is a single type of monomer. **Not a copolymer.**

11. **Styrene**: This is a single type of monomer. **Not a copolymer.**

12. **Polyisoprene**: This is a polymer made from isoprene, which is a single type of monomer. **Not a copolymer.**

### Step 3: Identify the Sets with Only Copolymers
From our analysis, the following options contain only copolymers:
- **Buna-N** (1,3-butadiene and acrylonitrile)
- **Buna-S** (styrene and 1,3-butadiene)
- **Nylon 6-6** (adipic acid and hexamethylene diamine)
- **Glyptal** (ethylene glycol and phthalic acid)

### Conclusion
The answer to the question is that the set containing only copolymers is **Buna-N, Buna-S, Nylon 6-6, and Glyptal**.

### Final Answer
**Option C: Buna-S, Nylon 6-6, Glyptal** contains only copolymers.

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