Demonstration 18.7

Purpose: To prepare Nylon.

Materials: 250-mL beaker, 50mL petroleum ether, 1mL sebacoyl chloride, stirring rod, 100-mL beaker, 1.1 g 1,6-hexanediamine, 10 mL 1M NaOH, food coloring, forceps, graduated cylinder, papers towels.

Safety Precautions: apron, goggles, fume safety, poison safety, chemical safety, open flame alert, disposal alert.

Disposal: Code A

Procedure: CAUTION: The vapors are hazardous. Use a fume hood for this demonstration. Goggles must be worn because the solution can easily splash into the eyes. In a 250-mL beaker, place 50 mL of petroleum ether. Add 1 mL of sebacoyl chloride to the petroleum ether. It is important that the solution be thoroughly mixed. In a 100-mL beaker, mix 10 mL of 1 M NaOH in 15 mL of H20. Dissolve 1.1 g of 1,6-hexanediamine in the H20 solution. Add a drop of food coloring to the H20 solution to help students see the H20 layer in the next step. Carefully pour the water solution down the side of the 250-mL beaker into the petroleum ether solution, without mixing the two. Using forceps, pick up the center of the film that forms at the interface of the two liquids. Slowly pull the nylon fiber from the beaker, and roll it up on a graduated cylinder that has a paper towel wrapped around it.

Results: A continuous thread of nylon is pulled from the center of the beaker. Students can observe the formation of the fiber at the interface of the two solvents.