Polypropylene:           

Polypropylene or PP, which are also olefins, offer a balance of properties rather any one outstanding characteristics. They are somewhat similar to higher density polyethylene, except that they are lighter in weight, have greater heat resistance and rigidity, resistance to fatigue and better resistance to environmental stress cracking. They are relatively low cost and have unlimited colourability. Very thin sheets of polypropylene are used as a dielectric within certain high performance pulse and low loss Radio Frequency capacitors. Although it is less tough than HDPE and less flexible than LDPE, it is much more brittle than HDPE.

Polypropylene is an excellent insulator and is stiffer than polyethylene. It is used in a wide variety of applications, including food packaging, textiles, plastic parts and reusable containers of various types, luggage, and hospital equipment, thermal pants and shirts made for the military, laboratory equipment, loudspeakers, automotive components, and polymer banknotes.