Which of the following are additional homopolymers?

Options

A. Teflon
B. `SBR`
C. `PVC`
D. Natural rubber

Explanation

To determine which of the given options are additional homopolymers, we need to follow these steps:

### Step 1: Understand the Definitions
- **Homopolymer**: A polymer that is made from a single type of monomer. For example, if we polymerize only one type of monomer, we get a homopolymer.
- **Addition Polymer**: A type of polymer formed by the addition of monomer molecules that contain double or triple bonds. This process does not involve the elimination of any small molecules.

### Step 2: Analyze the Options
1. **Teflon**: Teflon is made from the polymerization of tetrafluoroethylene, which is a single type of monomer. Therefore, Teflon is a homopolymer and also an addition polymer.

2. **SBR (Styrene-Butadiene Rubber)**: SBR is made from two different monomers: styrene and butadiene. Since it involves more than one type of monomer, SBR is not a homopolymer.

3. **PVC (Polyvinyl Chloride)**: PVC is made from the polymerization of vinyl chloride, which is a single type of monomer. Therefore, PVC is a homopolymer and also an addition polymer.

4. **Natural Rubber**: Natural rubber is primarily made from isoprene, which is a single type of monomer. Thus, natural rubber is a homopolymer and also an addition polymer.

### Step 3: Conclusion
From the analysis:
- Teflon (Correct)
- SBR (Incorrect)
- PVC (Correct)
- Natural Rubber (Correct)

So, the additional homopolymers from the options given are Teflon, PVC, and Natural Rubber.

### Final Answer:
The additional homopolymers are Teflon, PVC, and Natural Rubber.

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