The synthesis of which of the following polymers involves the repeated loss of small molecules?

Nylon-6,6

The correct answer is option 4. Nylon-6,6.

The synthesis of Nylon-6,6 involves a polycondensation reaction, which is a type of polymerization that typically involves the repeated loss of small molecules such as water or alcohol. In the case of Nylon-6,6, the monomers used are adipic acid and hexamethylenediamine.

Here is how the synthesis occurs:

Adipic Acid (HOOC-(CH₂)₄-COOH) + Hexamethylenediamine (H₂N-(CH₂)₆-NH₂): These two monomers react through a condensation reaction, where the carboxyl group (-COOH) of adipic acid reacts with the amino group (-NH₂) of hexamethylenediamine. This reaction results in the formation of a peptide bond (-CONH-) and the release of a water molecule (H₂O).

The formation of the peptide bond between the monomers results in the formation of a long chain polymer, with repeating units derived from both adipic acid and hexamethylenediamine.

The repeated loss of water molecules during the condensation polymerization process contributes to the growth of the polymer chains and the formation of Nylon-6,6. This process is characteristic of polycondensation reactions, where small molecules are eliminated as by-products.

The synthesis of Nylon-6,6 involves the repeated loss of small molecules (water molecules) during the condensation polymerization process. Therefore, Nylon-6,6 is the polymer among the options provided that involves the repeated loss of small molecules.