Polypropylene is a member of the class of polyolefins and a non-polar synthetic thermoplastic polymer. Is a white solid, which was prepared by polymerizing propylene industry. This occurs at low and medium pressures in the presence of organometallic catalysts. The propylene copolymers may be prepared by copolymerizing propylene and ethylene. Polypropylene and propylene copolymers produced stabilized, painted or unpainted.
Properties
PP - a plastic material that is highly durable flex and impact. It is also characterized by durability and good electrical properties over a wide temperature range. It has good gloss and transparency, is chemically stable and will not crack under the influence of the environment.
Process propylene polymerization occurs under conditions close to those used in the synthesis of IPA. In this case, a stereoregular (isotactic) polypropylene. This resin has a high melting point (175 ° C) and is easily crystallized. Crystalline polypropylene is the lightest of all known hard polymers having a relative density of 0.9. PP different hardness and high tensile strength. Isotactic polypropylene, because of the crystal structure retains good mechanical properties and shape of the melting temperature, so it can be subjected to ordinary sterilization. Polyethylene Polypropylene is superior in strength, but inferior to him in cold resistance (brittleness temperature of -5 to -15 ° C). This disadvantage can be eliminated by introducing ethylene units in the macromolecules of isotactic polypropylene.