Dacron is an example of:

Options

A. polyamides
B. polypropenes
C. polyacrylonitrile
D. polyesters .

Explanation

To solve the question "Dacron is an example of:", we will analyze the chemical structure and classification of Dacron.

### Step-by-Step Solution:

1. **Identify Dacron**: Dacron is a synthetic polymer that is commonly known as a type of polyester. It is primarily made from two monomers: ethylene glycol and terephthalic acid.

2. **Monomer Units**:
- **Ethylene Glycol**: The chemical structure of ethylene glycol is HO-CH2-CH2-OH. It contains two hydroxyl (–OH) groups.
- **Terephthalic Acid**: The chemical structure of terephthalic acid is C6H4(COOH)2, which can be represented as HOOC-C6H4-COOH. It contains two carboxylic acid (–COOH) groups.

3. **Polymer Formation**: Dacron is formed through a condensation polymerization reaction between ethylene glycol and terephthalic acid. During this reaction, water (H2O) is eliminated as a byproduct.

4. **Ester Linkage**: The reaction between the hydroxyl groups of ethylene glycol and the carboxylic acid groups of terephthalic acid leads to the formation of ester linkages. This is a characteristic feature of polyesters.

5. **Conclusion**: Since Dacron is formed from the polymerization of ethylene glycol and terephthalic acid, and it contains ester linkages, it is classified as a polyester.

### Final Answer:
Dacron is an example of a **polyester**.

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