Which of the following statements is not correct ?

Options

A. Caprolactam is the monomer of nylon-6
B. Terylene is a polyester polymer
C. Phenol-formaldehyde resin is known as bakelite
D. The monomer of natural rubber is butadiene.

Explanation

To determine which statement is not correct, we will analyze each of the given statements regarding polymers and their monomers.

### Step-by-Step Solution:

1. **Statement 1: Caprolactam is the monomer of nylon 6.**
- Caprolactam is indeed the monomer used to produce nylon 6 through a process called ring-opening polymerization. Therefore, this statement is **correct**.

2. **Statement 2: Pteriline is a polyester polymer.**
- Pteriline, also known as poly(ethylene terephthalate) (PET), is formed from the reaction of ethylene glycol and terephthalic acid, which are both esterified to form a polyester. Thus, this statement is **correct**.

3. **Statement 3: Phenol formaldehyde resin is known as Bakelite.**
- The resin formed from phenol and formaldehyde is indeed known as Bakelite, which is a type of thermosetting plastic. Therefore, this statement is **correct**.

4. **Statement 4: The monomer of natural rubber is butadiene.**
- Natural rubber is primarily made from isoprene (2-methyl-1,3-butadiene), not butadiene. Therefore, this statement is **incorrect**.

### Conclusion:
The statement that is not correct is **Statement 4**: "The monomer of natural rubber is butadiene."

### Final Answer:
**Option 4 is the correct answer for this question.**

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