Polypropylene

A thermoplastic similar to polyethylene but stiffer and with a higher softening point (temperature). Derived from the polymerization of propylene with a specific catalyst such as aluminum alkyl. Polypropylene has a lower density than polyethylene resins. Its chemical and electrical properties are similar to those of polyethylene. Its fluid resistance is somewhat superior. It is flammable, but flame-retardant grades have been formulated. It can be degraded by heat and light unless protected by antioxidants.