Which of the following are example of synthetic rubber?

Options

A. Polychloroprene
B. Polyacrylonitrile
C. Buna-N
D. cis- polysioprene

Explanation

To determine which of the given options are examples of synthetic rubber, we will analyze each option based on their chemical composition and classification.

### Step-by-Step Solution:

1. **Understanding Synthetic Rubber**:
- Synthetic rubber is a man-made elastomer that is produced from petroleum-based monomers. It is designed to mimic the properties of natural rubber but often has improved characteristics such as better heat resistance, chemical resistance, and durability.

2. **Analyzing the Options**:
- **Option 1: Polychloroprene**:
- Polychloroprene, commonly known as neoprene, is a type of synthetic rubber. It is produced from the polymerization of chloroprene (2-chloro-1,3-butadiene). Therefore, this option is an example of synthetic rubber.

- **Option 2: Polyacrylonitrile**:
- Polyacrylonitrile is a polymer made from the monomer acrylonitrile. It is primarily used in the production of fibers and is not classified as synthetic rubber. Thus, this option is not an example of synthetic rubber.

- **Option 3: BUNA-N**:
- BUNA-N is a synthetic rubber that is created from the copolymerization of 1,3-butadiene and acrylonitrile. It is widely used in applications requiring oil resistance. Therefore, this option is also an example of synthetic rubber.

- **Option 4: Cispolyisoprene**:
- Cispolyisoprene is essentially the same as natural rubber, which is derived from the latex of rubber trees. Since it is not a synthetic product, this option is not an example of synthetic rubber.

3. **Conclusion**:
- Based on the analysis, the examples of synthetic rubber from the given options are:
- **Option 1: Polychloroprene (Neoprene)**
- **Option 3: BUNA-N**

### Final Answer:
The correct examples of synthetic rubber are **Option 1 (Polychloroprene)** and **Option 3 (BUNA-N)**.

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