Nylon Synthesis

How to Make Nylon - Nylon Rope Trick

This is the three-dimensional molecular structure of nylon 6.
This is the three-dimensional molecular structure of nylon 6. YassineMrabe, Creative Commons License

Nylon is a polymer you can make yourself in the lab. A strand of nylon rope is pulled from the interface between two liquids. The demonstration sometimes is called the 'nylon rope trick' because you can pull a continuous rope of nylon from the liquid indefinitely. Close examination of the rope will reveal that is is a hollow polymer tube.

Nylon Materials

  • a solution made from 6 g sebacoyl chloride in 70 ml heptane
  • a solution made from 3 g 1,6-diaminohexane in 70 ml water
  • metal tweezers or forceps

Make Nylon

  1. Use equal volumes of the two solutions. Tilt the beaker containing the 1,6-diaminohexane solution and slowly pour the sebacoyl chloride solution down the side of the beaker so that it forms the top layer.
  2. Dip tweezers into the interface of the liquids and pull them up to form a strand of nylon. Continue to pull the tweezers away from the beaker to lengthen the strand. You may wish to wrap the nylon rope around a glass rod.
  3. Rinse the nylon with water, ethanol or methanol to remove the acid from the nylon. Be sure to rinse the nylon before handling it or storing it.

How the Nylon Rope Trick Works

Nylon is the name given to any synthetic polyamide. Acyl chloride from any dicarboxylic acid reacts via a substitution reaction with any amine to form a nylon polymer and HCl.

Safety and Disposal

The reactants are irritating to the skin, so wear gloves throughout the procedure.

Remaining liquid should be mixed to form nylon. The nylon should be washed prior to disposal. Any unreacted liquid should be neutralized prior to washing it down the drain. If the solution is basic, add sodium bisulfate. If the solution is acidic, add sodium carbonate.

Reference: Chemical Magic, 2nd Ed., Leonard A. Ford (1993) Dover Publications, Inc.

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