Learning focus
Develop accurate organic nomenclature, connect functional groups to reactions, draw structural and polymer formulae, interpret industrial processes and apply evidence to unfamiliar compounds.
Formation
A dicarboxylic acid reacts with a diamine. Each -COOH/-NH2 pair forms an amide link, -CONH-, and water. Repeated reaction forms a polyamide.
Nylon
Nylon is the required synthetic polyamide example. A displayed structure should show alternating carbon-containing residues joined by amide links.
Deducing monomers
Cut the polymer at C-N within each amide link and restore functional groups: the carbonyl side becomes -COOH and the nitrogen side becomes -NH2. Check that the resulting monomers are bifunctional.
Properties and use
Strong intermolecular attractions between polyamide chains can produce strong fibres. The syllabus mainly requires structure, linkage and monomer deduction rather than a detailed property mechanism.
High-value recall and connections
Essential recall: What monomers form nylon-type polyamides? A dicarboxylic acid and a diamine. What is the linkage? -CONH-. What by-product forms? Water. Practical connection: Identify every amide link in a nylon segment and deduce the diamine and dicarboxylic-acid monomers. Examination connection: An amide linkage contains both C=O and N-H in the chain.
Practical or data skill
Identify every amide link in a nylon segment and deduce the diamine and dicarboxylic-acid monomers.
Examination tip
An amide linkage contains both C=O and N-H in the chain.
Review questions and suggested answers
Question 1
What monomers form nylon-type polyamides?
Suggested answer
A dicarboxylic acid and a diamine.
Question 2
What is the linkage?
Suggested answer
-CONH-.
Question 3
What by-product forms?
Suggested answer
Water.
