Which fo the following sets contains only copolymers?

Options

A. `SBR`,Glyptal,Nylon-`6,6`
B. Poluthene ,Polyester,`PVC`
C. Nylon-`6`,Butyl rubber,Neoprene
D. Melmac,Bakelite,Teflon

Answer

To determine which set contains only copolymers, we need to understand what a copolymer is. A copolymer is a polymer that is made from two or more different types of monomeric units. Let's analyze the options given in the question step by step.

### Step-by-Step Solution:

1. **Identify the Definition of Copolymers**:
- Copolymers are formed from two or more different monomeric units.

2. **Analyze Each Option**:
- **Option A: Styrene Butadiene Rubber**:
- Made from 1,3-butadiene and styrene.
- Since it uses two different monomers, it is a copolymer.

- **Option B: Glyptal**:
- Made from ethylene glycol and phthalic acid.
- This also involves two different monomeric units, making it a copolymer.

- **Option C: Nylon 6-6**:
- Made from hexamethylene diamine and adipic acid.
- Again, this is formed from two different monomers, so it is a copolymer.

3. **Check Other Options**:
- **Polythene**:
- Made from ethene (a single monomer).
- Not a copolymer.

- **PVC (Polyvinyl Chloride)**:
- Made from vinyl chloride (a single monomer).
- Not a copolymer.

- **Nylon 6**:
- Made from caprolactam (a single monomer).
- Not a copolymer.

- **Neoprene**:
- Made from chloroprene (a single monomer).
- Not a copolymer.

- **Teflon**:
- Made from tetrafluoroethene (a single monomer).
- Not a copolymer.

- **Melamine Formaldehyde**:
- Made from melamine and formaldehyde (two different monomers).
- This is a copolymer.

- **Bakelite**:
- Made from phenol and formaldehyde (two different monomers).
- This is also a copolymer.

4. **Conclusion**:
- The only set that contains only copolymers is the one that includes Styrene Butadiene Rubber, Glyptal, and Nylon 6-6, as all these are formed from different monomeric units.

### Final Answer:
The correct answer is **Option A**: Styrene Butadiene Rubber, Glyptal, and Nylon 6-6.