Isoprene(2-methyl 1,3-butadiene) is a basic unit of the polymer rubber

Options

A. buna N rubber
B. buna S rubber
C. neoprene rubber
D. natural rubber

Answer

To solve the question regarding the basic unit of the polymer rubber, we need to identify which type of rubber is derived from isoprene (2-methyl-1,3-butadiene).

### Step-by-Step Solution:

1. **Understanding Isoprene**:
- Isoprene is chemically known as 2-methyl-1,3-butadiene. Its structure can be represented as:
\[ \text{CH}_2=C(CH_3)-CH=CH_2 \]
- This structure shows that isoprene contains two double bonds and a methyl group attached to the second carbon.

2. **Identifying the Polymers**:
- The question provides four options: Buna-N rubber, Buna-S rubber, Neoprene rubber, and Natural rubber. We need to determine which of these is based on isoprene.

3. **Natural Rubber**:
- Natural rubber is a polymer made from the polymerization of isoprene. When isoprene molecules undergo polymerization, they link together to form long chains, which is the structure of natural rubber.

4. **Other Rubbers**:
- **Buna-N Rubber**: This rubber is made from the copolymerization of butadiene and acrylonitrile.
- **Buna-S Rubber**: This rubber is formed from the copolymerization of butadiene and styrene.
- **Neoprene Rubber**: This rubber is derived from the polymerization of chloroprene (2-chloro-1,3-butadiene), not isoprene.

5. **Conclusion**:
- Since natural rubber is the only polymer listed that is directly derived from isoprene, we conclude that the basic unit of the polymer rubber is isoprene.

### Final Answer:
The basic unit of the polymer rubber is **Natural Rubber**, which is derived from isoprene.