Which of the following can not be used as plasticisers?

Options

A. Sodium nexametaphosphate
B. n-dibutylphthalate
C. Tricresyl phosphate
D. Diethyl-phthalate

Answer

To determine which of the following compounds cannot be used as a plasticizer, we will analyze each option provided:

1. **Sodium Hexametaphosphate**: This compound is primarily used as an industrial preservative and is not known for its plasticizing properties. Therefore, it does not function as a plasticizer.

2. **N-Dibutyl Phthalate**: This is a well-known plasticizer. It is commonly used in the production of flexible plastics due to its low toxicity and ability to enhance the flexibility and workability of plastic materials.

3. **Tri-Propyl Phosphate**: This compound is also recognized as a plasticizer. It helps to make plastics more flexible and resilient, which is a key characteristic of plasticizers.

4. **Diethyl Phthalate**: Similar to N-Dibutyl Phthalate, Diethyl Phthalate is another compound used as a plasticizer. It aids in improving the flexibility of plastic materials.

Based on the analysis above, the compound that cannot be used as a plasticizer is:

**Answer: Sodium Hexametaphosphate (Option A)**