Which polymer has a 'chiral' monomer (s) ?

Options

A. Nylon 6,6
B. Neoprene
C. PHBV
D. Buna - N

Answer

To determine which polymer has a chiral monomer, we will analyze the monomers of the given polymers one by one. A chiral monomer has a carbon atom that is bonded to four different substituents.

### Step 1: Identify the monomers of the given polymers.
1. **Nylon 6,6**: The monomers are hexamethylenediamine and adipic acid.
2. **Neoprene**: The monomer is chloroprene.
3. **PHBV (Poly-3-hydroxybutyrate-co-3-hydroxyvalerate)**: The monomers are 3-hydroxybutanoic acid and 3-hydroxyvaleric acid.
4. **BUNA-N**: The monomer is acrylonitrile.

### Step 2: Analyze each monomer for chirality.
1. **Hexamethylenediamine**: The structure has two amine groups and does not have a carbon atom bonded to four different substituents. Therefore, it is **not chiral**.

2. **Adipic acid**: The structure has two carboxylic acid groups and does not have a carbon atom bonded to four different substituents. Therefore, it is **not chiral**.

3. **Chloroprene**: The structure has a double bond and does not have a carbon atom bonded to four different substituents. Therefore, it is **not chiral**.

4. **3-Hydroxybutanoic acid**: This monomer has a carbon atom that is bonded to an OH group, a hydrogen atom, a CH3 group, and a CH2COOH group. Since this carbon atom has four different substituents, it is **chiral**.

5. **3-Hydroxyvaleric acid**: Similar to 3-hydroxybutanoic acid, this monomer also has a chiral center.

6. **Acrylonitrile**: The structure has a double bond and does not have a carbon atom bonded to four different substituents. Therefore, it is **not chiral**.

### Conclusion:
The polymer **PHBV** has chiral monomers (3-hydroxybutanoic acid and 3-hydroxyvaleric acid).

### Final Answer:
**PHBV (Poly-3-hydroxybutyrate-co-3-hydroxyvalerate)** has chiral monomers.

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