Nylon-6, 6 is

Options

A. Polyamide
B. Polyester
C. Polystyrene
D. Polyvinyl

Explanation

To answer the question "Nylon-6, 6 is?", we need to analyze the characteristics and classification of Nylon-6,6.

### Step-by-Step Solution:

1. **Identify the Type of Polymer**:
- Nylon-6,6 is a type of polymer. Polymers are large molecules formed by repeating structural units called monomers.

2. **Determine the Monomer Units**:
- Nylon-6,6 is synthesized from two specific monomers: hexamethylenediamine and adipic acid.
- Hexamethylenediamine has the formula H2N-(CH2)6-NH2, and adipic acid has the formula HOOC-(CH2)4-COOH.

3. **Understand the Polymerization Process**:
- During the polymerization process, one hydrogen atom from the amine group (NH2) of hexamethylenediamine and one hydroxyl group (OH) from the carboxylic acid (COOH) of adipic acid are removed to form water (H2O).
- This reaction creates an amide bond (–CO–NH–), linking the two monomers together.

4. **Recognize the Linkages**:
- The repeating unit in Nylon-6,6 contains amide linkages (–CO–NH–). This is a key feature that classifies it as a polyamide.

5. **Classify Nylon-6,6**:
- Since Nylon-6,6 contains a large number of amide linkages, it is classified as a polyamide.

6. **Conclusion**:
- Therefore, the correct answer to the question "Nylon-6,6 is?" is that it is a polyamide.

### Final Answer:
Nylon-6,6 is a polyamide.