Metalwork - Materials - Polymer Experiments

As with all experiments you need to set yourself up with a number of items first. There is a list and diagrams of what you need below.. You will also need pieces of each of the following types of polymer : Acrylic, Polythene, P.V.C., Nylon, Phenolic Plastic, Polyester, Polyurethane Foam
  • Knife
  • Bowl of Water
  • Bunsen Burner
  • Tongs
Knife Bowl of Water
tongs Bunsen Burner

Test 1 : Appearance of the sample

Look at the sample and see if it is opaque, transparent or translucent.

Polymer Appearance
Acrylic Can be crystal clear, or opaque if colour pigments are added. It has a glossy surface.
Polyethylene If the piece is thich then it is translucent or opaque. If is is film then it is transparent.
PVC Transparent unless colour pigments have been added.
Nylon Opaque.
Phenolic Resins Opaque and dark coloured.
Polyester If the Polyester is reinforced then you should be able to see the fibre reinforcement.
Polyurethane Foam Opaque.

Test 2 : Feel the sample

Feel the sample, try to bend it, scratch your nail on it.

Polymer Description
Acrylic Stiff, hard, doesn't mark when scratched with a finger nail.
Polyethylene LDPE : reasonably flexible, soft, waxy feel.
HDPE : stiff and hard.
PVC Unplasticised : stiff and hard
Plasticised : flexible and soft.
Nylon Stiff, hard and greasy.
Phenolic Resins Stiff and hard.
Polyester Stiff and hard.
Polyurethane Foam Usually soft and rigid, but rigidity can be varied as needed.

Test 3 : Cut the sample with the knife.

Take note of how the polymer breaks off.  Please be careful with the knife!!!

Polymer Cutting Description
Acrylic Splinters leaving a jagged edge on cutting.
Polyethyene LDPE : very easily and smoothly cut.
HDPE : easily cut with smooth edges.
PVC Unplasticised : easy to cut with smooth edges.
Plasticised : very easily cut with smooth edges.
Nylon Fairly easy to cut eith smooth edges.
Phenolic Resins Flakes on cutting.
Polyester Difficult to cut as it is brittle.
Polyurethane Foam Does not crumble on cutting.

Test 4 : Drop the sample in a bowl of water.

Polymer Floats or Sinks
Acrylic Sinks
Polyethyene Floats
PVC Sinks
Nylon Sinks
Phenolic Resins Sinks
Polyester Sinks
Polyurethane Foam Floats

Test 5 : Try burning a small sample

N.B. When conducting this experiment be very careful. If at all possible go to the science room where they should have a fume cupbord. When smelling possible toxic fumes, you should hold the item in question a good distance from you and waft the fumes towards yourself with your hand. Make sure you are in a well ventillated area.

Polymer Smell
Acrylic Burns readily, not self-extinguishing, drips continue to burn, yellow flame, strong vaguely fruity odour, frothing especially just after the flame is extinguished.
Polyethyene Not self-extinguishing, molten droplets which usually go out when they fall, blue flame with a yellow tip and little smoke, smell of a burning candle when the flame is extinguished.
PVC Unplasticised : burns with difficulty, self extinguishing, yellow flame, blue green at bottom edges, unpleasand odour of hydrochloric acid.
Plasticised : burning behaviour will depend on the plasticiser, may continue to burn after the flame has been removed.
Nylon Difficult to ignite, not self-extinguishing, melts to a free flowing liquid which drips carrying the flame with it, blue flame with a yellow tip, odour of burning hair.
Phenolic Resins Burns with difficulty, self-extinguishing, odour of carbolic acid.
Polyester Burns readily, self-extinguishing, smokey flame, fruity odour.
Polyurethane Foam Not self-extinguishing, clear yellow flame, acrid odour.