Which of the following is chain growth polymer?

Options

A. Polypropylene
B. Nylon-6,6
C. Terylene
D. Glyptal

Answer

To determine which of the following is a chain growth polymer, we will analyze each option based on the type of polymerization involved.

### Step-by-Step Solution:

1. **Understand the Types of Polymerization**:
- There are two main types of polymerization: **chain growth polymerization** and **step growth polymerization**.
- Chain growth polymerization involves three main steps: initialization, propagation, and termination. It typically involves the repetitive addition of the same monomeric unit.
- Step growth polymerization involves the reaction of monomers to form dimers, trimers, and eventually polymers, often with the elimination of small molecules like water or alcohol.

2. **Analyze the Given Options**:
- **Gliptal**: This is formed from ethylene glycol and phthalic acid through condensation polymerization, which involves the removal of water. Therefore, it is a **step growth polymer**.
- **Pterilene**: This is produced from ethylene glycol and terephthalic acid, also through condensation polymerization. It also involves the removal of water, making it a **step growth polymer**.
- **Nylon 6,6**: This is formed from adipic acid and hexamethylene diamine, again through condensation polymerization with the removal of water. Thus, it is also a **step growth polymer**.
- **Polypropylene**: This polymer is formed from the repetitive addition of propylene monomers. The process involves chain growth polymerization, where the same monomeric unit (propylene) is added repetitively to form the polymer. Therefore, it is a **chain growth polymer**.

3. **Conclusion**:
- Among the options analyzed, **polypropylene** is the only chain growth polymer.

### Final Answer:
The chain growth polymer from the options provided is **polypropylene**.

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