Which of the following is a chain-growth polymer?

Options

A. Nylon
B. Dacron
C. Glyptal
D. Polypropylene

Answer

To determine which of the following is a chain-growth polymer, we will analyze the definition of chain-growth polymerization and the given options.

### Step-by-Step Solution:

1. **Understanding Chain-Growth Polymerization**:
- Chain-growth polymerization involves the linking of monomers that contain double or triple bonds. This process allows for the rapid growth of polymer chains as monomers add to the active site of the growing chain.

2. **Identifying Examples of Chain-Growth Polymers**:
- Common examples of chain-growth polymers include polypropylene, polystyrene, and polyvinyl chloride (PVC). These polymers are formed through the polymerization of their respective monomers.

3. **Analyzing the Options**:
- We are given several options to choose from. Let's examine each one:
- **Nylon**: This is a synthetic polymer formed through step-growth polymerization. It is made from the reaction of diamines and dicarboxylic acids.
- **Dacron**: This is a polyester, also produced through step-growth polymerization, specifically from the reaction of diols and dicarboxylic acids.
- **Gallipedals**: This term seems to be a misrepresentation or confusion with another polymer, but it is also associated with step-growth polymerization.
- **Polypropylene**: This is a well-known chain-growth polymer formed from the polymerization of propylene monomers.

4. **Conclusion**:
- After analyzing the options, we find that **Polypropylene** is the only chain-growth polymer among the listed options. Therefore, the correct answer is **Polypropylene**.

### Final Answer:
- The chain-growth polymer among the options is **Polypropylene**.