Dacron is continuous filament yarn used in curtains, dress fabrics and pressure fire hoses. The reaction for preparing Dacron is by the combination of which of the following?

Options

A. Hexamethylene diamene and adipic acid
B. Caprolactum
C. Phenol and formaldehyde
D. Ethylene glycol and terephthalic acid

Answer

To prepare Dacron, which is a type of polyester, we need to understand the monomeric units involved in its synthesis. Dacron is formed through the condensation polymerization of two specific monomers: terephthalic acid and ethylene glycol.

### Step-by-Step Solution:

1. **Identify the Monomers**:
- The two monomers required for the synthesis of Dacron are:
- **Terephthalic Acid** (C8H6O4)
- **Ethylene Glycol** (C2H6O2)

2. **Understand the Reaction Type**:
- The reaction that occurs to form Dacron is known as **condensation polymerization**. In this process, monomers react to form a polymer while releasing small molecules, typically water.

3. **Write the Reaction**:
- The reaction can be represented as:
\[ n \text{(C}_6\text{H}_4\text{(COOH)}_2) + n \text{(C}_2\text{H}_6\text{O}_2) \rightarrow \text{Dacron} + n \text{H}_2\text{O} \]
- Here, 'n' represents the number of repeating units.

4. **Resulting Structure**:
- After the condensation reaction, the structure of Dacron can be represented as:
\[ -\text{O}-\text{C}_6\text{H}_4-\text{C(O)O}-\text{CH}_2-\text{CH}_2-\text{O}-\text{C(O)O}-\text{C}_6\text{H}_4-\text{O}- \]
- This structure shows the repeating units of the polymer chain formed by the linkage of the monomers.

5. **Conclusion**:
- Therefore, Dacron is synthesized from the combination of **terephthalic acid** and **ethylene glycol** through condensation polymerization.