Some FR agents increase resistance to fire by decreasing the rate of decomposition of the burning material. Other FR agents slow the oxidation process by capturing free radicals. Still others release water of hydration, which carries away heat. The first part of this experiment involves testing the flammability of a plastic with and without a FR agent, then the testing of some other common plastics, which may or may not contain FR agents. A plastic film may also contain added plasticizer to modify the properties of the film.
Plasticizers alter properties of a polymer by altering the structure of the polymer.
A plasticizer can decrease the rigidity of the polymer and increase the toughness. The second part of this experiment involves testing changes in the tensile properties of a plastic film due to the presence of an added plasticizer. Cut four pieces of aluminum foil, each about 12 cm x 15 cm. Place one of the pieces of foil on a hot plate and turn the plate on to medium, making adjustments later as needed. Put one FR-treated polystyrene pellet on the foil and occasionally probe the pellet with a stirring rood until it is softened on the top.