Physical Properties of Cottonseed Oil

Cottonseed oil is mainly used as a salad, cooking, and frying oil, which represents more than 90 percent of its production, reports the National Cottonseed Products Association. Cottonseed oil is odorless, colorless to pale-yellow, and like most oils it floats in water. According to CAMEO Chemicals, the physical properties of this oil include a high boiling point and low vapor pressure, autoignition temperature, and melting and freezing points.

Autoignition Temperature

• The autoignition temperature refers to the amount of heat a substance needs to self-ignite, producing a hot flame without the help of any external source, reports chemical engineer George Wypych Ph.D. in the "Handbook of Solvents." The autoignition temperature for cottonseed oil is 650 degrees Fahrenheit, according to CAMEO Chemicals.

Vapor Pressure and Boiling Point

• The vapor pressure of a substance relates to the quantity of pressure it can uphold when in the form of vapor. This physical property is related to another one, the boiling point, which is the quantity of temperature a substance need to boil and evaporate. According to "Perry's Chemical Engineers' Handbook," the higher the vapor pressure of a substance is, the lower its boiling point will be. Cottonseed oil has a vapor pressure of 5.17 mmHg (millimeters of mercury) or 689 Pa (Pascal), according to CAMEO Chemicals. Its boiling point is 1,864 degrees Fahrenheit, reports Free Patents Online.

Melting and Freezing Points

• Melting and freezing points values are the same, when identifying a substance. They represent the temperature necessary to turn a substance from a solid to a liquid state or vice versa. Cottonseed oil freezes at 32 degrees Fahrenheit, according to CAMEO Chemicals. When in a solid state, cottonseed oil needs the same 32 degrees Fahrenheit to start to melt.