DP2.1 Making nylon

A nylon is made from its monomers by condensation polymerisation. You may already have done this or a similar experiment in an earlier course. If so, you can omit this activity and go on to Activity DP2.2.

 

Requirements

• 5 cm3 beaker

decanedioyl dichloride, 5 solution in cyclohexane (1 cm3)

• 1,6-diaminohexane, 5% solution in 0.5 mol dm-3 sodium carbonate solution (1 cm3)

glass rod or test-tube

tweezers

access to fume cupboard

protective gloves

 

What you do

1        Pour about 1 cm3 of the 1,6-diaminohexane solution (CARE Irritant) into a 5 cm3 beaker.

 

2        Carefully add an equal volume of the decanedioyl dichloride solution to the beaker. (CARE Decanedioyl dichloride has an irritating vapour. The vapour is a powerful lachrymator (eye irritant) and this effect is often delayed.  Perform this part of the activity in a fume cupboard) Two separate layers will form. Do not mix them.

 

3        Use a pair of tweezers to remove the nylon film which forms where the two layers are in contact. Do this slowly and hook the nylon thread which forms onto a glass rod or a test-tube.  Slowly wind the thread around the rod. As the nylon is removed more forms at the solution interface, so you should be able to keep on winding for some time.

 

4        Once you have made some nylon it needs to be washed thoroughly with tap water. Take care not to touch the nylon because it forms as a hollow tube, and there will still be some chemicals trapped in the middle.

 

Questions

a        Write out an equation to show the formation of nylon in this activity.

nNH2-(CH2)6-NH2 + nCOCl-(CH2)8-COCl →

n(-(CH2)6-HNOC-(CH2)8-CONH-) + 2nHCl

 

b        What is the name of the nylon you have made?

Nylon 6,10