Common examples of semi-synthetic polymers are

Options

A. cellulose and starch
B. cellulose acetate and cellulose nitrate
C. buna-N and buna-S
D. cellulose nitrate and buna-S

Answer

To answer the question regarding common examples of semi-synthetic polymers, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Semi-Synthetic Polymers**:
- Semi-synthetic polymers are derived from naturally occurring polymers that have been chemically modified. This means they start as natural materials but undergo a chemical process to enhance or change their properties.

2. **Identify Examples of Semi-Synthetic Polymers**:
- Common examples of semi-synthetic polymers include:
- **Cellulose Acetate**: This is made from cellulose, which is a natural polymer found in plant cell walls. Cellulose is chemically modified by acetylation to produce cellulose acetate.
- **Cellulose Nitrate**: Similar to cellulose acetate, cellulose nitrate is also derived from cellulose but is modified through nitration.

3. **Evaluate the Options Provided**:
- **Option 1**: Cellulose and Starch - Both are naturally occurring polymers, not semi-synthetic.
- **Option 2**: Cellulose Acetate and Cellulose Nitrate - Both are semi-synthetic polymers.
- **Option 3**: Buna N and Buna S - These are synthetic (man-made) polymers, not semi-synthetic.
- **Option 4**: Cellulose Nitrate and Buna S - Cellulose nitrate is semi-synthetic, but Buna S is synthetic.

4. **Select the Correct Answer**:
- Based on the evaluation, the correct answer is **Option 2: Cellulose Acetate and Cellulose Nitrate**.

### Final Answer:
Common examples of semi-synthetic polymers are **Cellulose Acetate and Cellulose Nitrate**.

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