Which is not an example of addition polymer?

Options

A. Neoprene
B. PMMA
C. PVC
D. Dacron

Answer

To determine which of the given options is not an example of an addition polymer, we need to understand what addition polymers are and analyze each option provided.

### Step-by-Step Solution:

1. **Define Addition Polymers**:
Addition polymers are formed through the process of chain growth polymerization where monomers with unsaturated bonds (like double bonds) react to form a polymer without the release of any by-products.

2. **Analyze the Options**:
- **Option 1: Neoprene**
- Neoprene is made from the monomer chloroprene. During its polymerization, the double bond in chloroprene opens up and links together to form a long chain. No by-products are released. Therefore, neoprene is an addition polymer.

- **Option 2: Polymethylmethacrylate (PMMA)**
- PMMA is formed from the monomer methyl methacrylate. Similar to neoprene, the polymerization involves the opening of a double bond and does not release any by-products. Thus, PMMA is also an addition polymer.

- **Option 3: Polyvinyl Chloride (PVC)**
- PVC is produced from the polymerization of vinyl chloride. The process involves breaking the double bond in vinyl chloride to form a long chain without releasing any by-products. Therefore, PVC is an addition polymer as well.

- **Option 4: Dacron**
- Dacron is made from the reaction between terephthalic acid and ethylene glycol. This reaction results in the formation of ester linkages and releases water (H2O) as a by-product. Since a by-product is formed, Dacron is classified as a condensation polymer, not an addition polymer.

3. **Conclusion**:
Based on the analysis, the option that is not an example of an addition polymer is **Dacron**.

### Final Answer:
**Dacron** is not an example of an addition polymer.

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