A separatory funnel made of polypropylene (PP) is a laboratory apparatus used for liquid-liquid extractions. The funnel is designed with a stopcock or a valve at the bottom that allows for precise control of the flow of liquids. The separatory funnel is filled with the mixture to be extracted, and the two immiscible liquids are allowed to separate into different layers.

The stopcock is then used to selectively remove one layer of liquid, leaving the other layer undisturbed. The use of a PP material makes the separatory funnel durable, lightweight, and resistant to chemicals commonly used in the laboratory.

Additionally, polypropylene is chemically resistant and can be used with a wide range of liquids without risk of contamination or corrosion.