Which of the following is are not an elastomer ?

Options

A. Bakellite
B. Polyethylene
C. Nylon-6
D. natural rubber

Explanation

To determine which of the following options are not elastomers, we will analyze each option based on their properties and classifications.

### Step-by-Step Solution:

1. **Understanding Elastomers**:
- Elastomers are polymers that can be stretched and return to their original shape. They are characterized by weak intermolecular forces which allow for flexibility and elasticity.

2. **Analyzing the Options**:
- **Option 1: Bakelite**
- Bakelite is a thermosetting polymer. Thermosetting polymers do not have the elastic properties of elastomers because they cannot be remolded or reshaped after curing. Therefore, Bakelite is **not an elastomer**.

- **Option 2: Polyethylene**
- Polyethylene is a thermoplastic polymer. While it can be flexible, it does not have the same elastic properties as elastomers. Thus, polyethylene is **not an elastomer**.

- **Option 3: Nylon-6**
- Nylon-6 is a synthetic fiber and is classified as a thermoplastic. It has good tensile strength but lacks the elastic properties characteristic of elastomers. Therefore, nylon-6 is **not an elastomer**.

- **Option 4: Natural Rubber**
- Natural rubber is a well-known elastomer derived from the polymerization of isoprene. It exhibits significant elasticity and can be stretched extensively without permanent deformation. Hence, natural rubber **is an elastomer**.

3. **Conclusion**:
- Based on the analysis, the options that are **not elastomers** are Bakelite, Polyethylene, and Nylon-6.

### Final Answer:
The options that are not elastomers are:
**Bakelite, Polyethylene, and Nylon-6.**

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