Freon Reaction to Plastics
A brief summary of the effect of Freon compounds on various plastic materials follows. However, compatibility should be tested for specific applications. Differences in polymer structure and molecular weight, plasticizers, temperature, and pressure may alter the resistance of the plastic toward the Freon compound.
Teflon TFE-fluorocarbon resin: No swelling observed when submerged in Freon liquids, but some diffusion found with Freon 12 and Freon 22.
Polychlorotrifluoroethylene: Slight swelling, but generally suitable for use with Freon compounds.
Polyvinyl alcohol: Not affected by the Freon compounds, but very sensitive to water. Used especially in tubing with an outer protective coating.
Vinyl: Resistance to the Freon compounds depends on vinyl type and plasticizer. Considerable variation is found. Samples should be tested before use.
Orlon acrylic fiber: Generally suitable for use with the Freon compounds.
Nylon: Generally suitable for use with Freon compounds, but may tend to become brittle at high temperatures in the presence of air or water. Tests at 250°F (121°C) with Freon 12 and Freon 22 showed the presence of water or alcohol to be undesirable. Adequate testing should be carried out.
Polyethylene: May be suitable for some applications at room temperatures. However, it should be thoroughly tested since greatly different results have been found with different samples.
Lucite acrylic resin (methacrylate polymers): Dissolved by Freon 22. However, it is generally suitable for use with Freon 12 and Freon 114 for short exposure. On long exposure, it tends to crack, craze, and become cloudy. Use with Freon 113 may be questionable. It probably should not be used with Freon 11.
Cast Lucite acrylic resin: It is much more resistant to the effect of solvents than extruded resin. It can probably be used with most of the
Polystyrene: Considerable variation found in individual samples. However, it is generally not suited for use with Freon compounds. Some applications might be all right with Freon 114.
Phenolic resins: Usually not affected by the Freon compounds. However, composition of resins of this type may be quite different. Samples should be tested before use.
Epoxy resins: Resistant to most solvents and entirely suitable for use with the Freon compounds.
Cellulose acetate or nitrate: Suitable for use with Freon compounds. Delrin-acetal resin: Suitable for use with Freon compounds under most conditions.
Elastomers: Considerable variation is found in the effect of the Freon compounds on elastomers. The effect depends on the particular compound and elastomer type. In nearly all cases a satisfactory combination can be found. In some instances the presence of other materials, such as oils, may give unexpected results. Thus, preliminary testing of the system involved is recommended.
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