Question

Write a note a Gabriel phthalimide synthesis.

What are biodegradable polymers and non-biodegradable polymers? Write one example of each.

Explain cationic detergents.

Answer 1

Gabriel phthalimide synthesis: This synthesis is useful to get pure amino acids. The reaction involves the preparation of primary amines free from secondary and tertiary amines by using the reaction between alkyl halides with alkali metal phthalimide and subsequent hydrolysis.

Mechanism of Gabriel phthalimide ( Refer image).

For example, phthalimide is firstly treated with alcoholic $KOH$ to form potassium phthalimide which on further reaction with ethyl iodide gives N-ethyl phthalimide. The product N-ethylphthalimide is hydrolysed with dilute $HCl$ to form primary amine, i.e., ethylamine. This reaction is known as Gabriel phthalimide synthesis.

Biodegradable polymers: polymers that disintegrate by themselves after a certain period of time due to environmental degradation are called biodegradable polymers.

Non-biodegradable polymers: Polymers that do not disintegrate by themselves after a certain period are called non-biodegradable polymers.
Example of Biodegradable polymers: $PHBV$ i.e.

Example of Non-Biodegradable Polymers: Bakelite, Terylene, Nylon.

Cationic detergents: Cationic detergents are quaternary ammonium salts of amines with chlorides, acetates or bromides as anions. Cations are long-chain hydrocarbons and a positive charge on the nitrogen atom. Cetyltrimethylammonium chloride is used in hair conditioners.