For natural polymers PDI is generally

Options

A. 0
B. 1
C. 100
D. 1000

Explanation

To determine the Polydispersity Index (PDI) for natural polymers, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of PDI**:
- The Polydispersity Index (PDI) is a measure of the distribution of molecular mass in a given sample of polymers. It is calculated as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).
- Formula:
\[ PDI = \frac{M_w}{M_n} \]

2. **Identify the Types of Molecular Weights**:
- **Weight Average Molecular Weight (Mw)**: This is calculated by taking the total weight of the polymer sample divided by the sum of the individual weights of the polymers.
- **Number Average Molecular Weight (Mn)**: This is calculated by taking the total weight of all the polymers in the sample divided by the number of polymer molecules in the sample.

3. **Determine the PDI Value**:
- If the PDI is equal to 1, the sample is considered monodisperse, meaning all the polymer chains have the same length. If PDI is greater than 1, the sample is polydisperse, indicating a variety of chain lengths.

4. **Evaluate Natural Polymers**:
- For natural polymers, such as natural rubber, the PDI is generally found to be around 1. This indicates that natural rubber is monodisperse and homogeneous.

5. **Conclusion**:
- Therefore, for natural polymers, the PDI is generally 1.

### Final Answer:
For natural polymers, the PDI is generally 1.