Question

A polypeptide is also called a polyamide. Nylon is also an example of a polyamide. What is a polyamide? Consider a poly hydrocarbon, polyester, and a polyamide. Assuming average chain lengths are equal, which polymer would you expect to make the strongest fibbers and which polymer would you expect to make the weakest fibre? Explain.

Short answer

The weakest fiber is poly hydrocarbon because chains from London dispersion force, medium forces has polyester because it forms dipole-dipole interactions. The strongest fiber is Polyamide because it forms strong hydrogen bonds.

Step-by-step solution

Define Polyamide

A polyamide is a polymer with repeating units linked by amide bonds.

To see which fiber is the strongest and which one is the weakest we have to determine intermolecular bonds.

Polyester has polar parts in the chain. Therefore, two chains will be connected via dipole-dipole interactions.

Polyamide has polar parts as well, but it forms very strong hydrogen bonds. This type of intermolecular bonds is the strongest among these three types of polymers.

The weakest intermolecular bond is formed between two poly hydrocarbon chains. These chains are not polar and they form only weak London dispersion forces.

Illustration of Polyester, Polyamide and Polyhydrocarbon

Illustration of Polyester, Polyamide and Polyhydrocarbon

Therefore, the weakest fiber is poly hydrocarbon because chains from London dispersion force, medium forces has polyester because it forms dipole-dipole interactions. The strongest fiber is Polyamide because it forms strong hydrogen bonds.