Buna-S is a polymer of :

Options

A. Butadiene only
B. Butadiene and nitryl
C. Styrene only
D. Butadiene and styrene

Answer

To determine the polymer Buna-S, we need to identify the monomeric units that combine to form it. Here’s the step-by-step solution:

### Step 1: Identify the Monomers
Buna-S is formed from two specific monomers:
- **Styrene**: The chemical structure of styrene is C6H5-CH=CH2. It consists of a phenyl group (C6H5) attached to a vinyl group (CH=CH2).
- **Butadiene**: The chemical structure of butadiene is CH2=CH-CH=CH2. It is a diene with two double bonds.

### Step 2: Understand the Polymerization Process
When styrene and butadiene undergo polymerization, they combine through their double bonds to form a copolymer. This process involves the breaking of the double bonds in both monomers, allowing them to link together.

### Step 3: Write the Structure of Buna-S
The resulting polymer, Buna-S, can be represented as follows:
- The structure includes alternating units of styrene and butadiene, which can be depicted as:

CH2=CH-CH(C6H5)-CH=CH2

This structure shows how the styrene and butadiene units are arranged in the polymer chain.

### Step 4: Application of Buna-S
Buna-S is primarily used in the manufacture of tires due to its durability and resistance to wear.

### Conclusion
Thus, the correct answer to the question "Buna-S is a polymer of:" is:
**D. Butadiene and Styrene**

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