Which of the following has ester linkage ?

Options

A. Nylon-6,6
B. Bakelite
C. Terylene
D. PVC

Explanation

To determine which of the given options has an ester linkage, we need to analyze each option and check for the presence of the ester functional group, which is characterized by the -COO- bond.

### Step-by-Step Solution:

1. **Understanding Ester Linkage**:
- An ester linkage is formed when a carboxylic acid reacts with an alcohol, resulting in the formation of an -COO- group. The general structure can be represented as RCOOR', where R and R' are hydrocarbon chains.

2. **Analyzing Option 1: Nylon 6-6**:
- Nylon 6-6 is a polyamide, which means it contains amide linkages (-CONH-).
- The structure includes repeating units with -NH- and does not show any -COO- bond.
- **Conclusion**: Nylon 6-6 does not have an ester linkage.

3. **Analyzing Option 2: Bakelite**:
- Bakelite is a phenolic resin and does not contain any ester linkages.
- Its structure is primarily composed of phenolic groups and methylene bridges, but lacks the -COO- bond characteristic of esters.
- **Conclusion**: Bakelite does not have an ester linkage.

4. **Analyzing Option 3: Pterulin**:
- Pterulin, also known as dekaren, contains an ester linkage in its structure.
- The presence of -COO- indicates that it is a polyester, confirming the presence of the ester bond.
- **Conclusion**: Pterulin has an ester linkage.

5. **Analyzing Option 4: PVC (Polyvinyl Chloride)**:
- PVC is a polymer made from vinyl chloride monomers and does not contain ester linkages.
- Its structure consists of repeating units of -CH2-CH- with chlorine atoms, but no -COO- bond is present.
- **Conclusion**: PVC does not have an ester linkage.

### Final Answer:
- The option that has an ester linkage is **Option 3: Pterulin**.