Nylon Rope Trick
Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff
Categories: Organic Chemistry, Polymers
Alternative titles: Interfacial Polymerization of Nylon
Summary
The Nylon Rope Trick demonstrates interfacial polymerization, where nylon is formed at the boundary between two immiscible solutions: aqueous 1,6-diaminohexane and adipoyl chloride dissolved in cyclohexane. A continuous strand of nylon can be pulled from the liquid interface, creating a dramatic visual display of polymer formation.
Procedure
- Pour 25 mL of 5% aqueous 1,6-diaminohexane into a crystallizing dish.
- Carefully layer 25 mL of 5% adipoyl chloride in cyclohexane on top, ensuring the two solutions do not mix.
- At the interface, a thin film of nylon will form.
- Using forceps, grasp the nylon film and gently pull upward in a steady motion.
- Wind the continuous nylon thread around a test tube or roller to collect the polymer.
Links
Nylon Rope Trick - Wisconsin Mrsec (Education):
Carolina Science - Nylon Synthesis Chemistry Demo:
📄 Nylon Rope Trick - University of Washington: https://chem.washington.edu/lecture-demos/nylon-rope-trick
Variations
- Compare interfacial polymerization with bulk polymerization methods.
Safety Precautions
- Adipoyl chloride is corrosive and a lachrymator - avoid inhalation and skin contact.
- Cyclohexane is flammable and malodorous—keep away from flames and work in a well-ventilated area.
- 1,6-diaminohexane is corrosive - wear gloves, goggles, and a lab coat.
- Use an absorptive pad to contain spills and dispose of chemicals properly.
Questions to Consider
- Why does nylon form at the interface between the two layers? (The monomers react only at the boundary where they come into contact, producing a thin polymer film.)
- What type of reaction produces nylon in this demonstration? (Condensation polymerization, forming amide bonds.)
- Why is this demonstration called the “Nylon Rope Trick”? (Because a long strand of nylon can be pulled continuously like a rope.)
- What are some real-world applications of nylon? (Clothing, ropes, fishing line, engineering plastics.)