- Country of manufactureChina
Polypropylene (PP) is a synthetic thermoplastic non-polar polymer belonging to the class of polyolefins. The product of polymerization of propylene. The solid is white.
Polypropylene is produced in the industry by polymerization of propylene using Ziegler-Natta catalysts or metallocene catalysts. The polymerization takes place at a pressure of 10 atm. And temperature up to 80 ºС. The way of PP production with Ziegler-Natta catalyst was invented in 1957. Thanks to the inventions of Ziegler and Natt, it became possible to produce isotactic polypropylene.
The spatial location of the side groups (CH3-) with respect to the main chain is decisive for the properties of the polymer. There are isotactic, syndiotactic and atactic polypropylene. The main and most important variety is a PP with an isotactic structure. Isotactic polypropylene has a high degree of crystallinity, high strength, hardness and heat resistance. Atactic PP is a very flexible, soft and sticky product.
In industry, a polymer is obtained, consisting essentially of macromolecules of an isotactic structure.
Polypropylene has a high resistance to acids, alkalis, salt solutions and other inorganic aggressive media. At room temperature it does not dissolve in organic liquids, swells and dissolves at elevated temperatures in some solvents, for example, in benzene, carbon tetrachloride, ether.
PP has a low moisture absorption. Characterized by good electrical insulation properties in a wide range of temperatures.
PP is available in the form of colored and unpainted granules. Pigments or organic dyes are used for staining. Light crystallizing material. There are homopolymer (isotactic polypropylene), block copolymer with ethylene (copolymer), as well as a random copolymer, metallocene polypropylene (mPP), crosslinked polypropylene (PP-X, PP-XMOD).
Polypropylene has good mechanical properties. Homopolymer has increased stiffness, it can be transparent, but fragile at low temperatures. The block copolymer has a high impact resistance and can be used at low temperatures. Has low wear resistance. Easily recyclable. Transparency of the material is provided by introducing a nucleating agent (nucleator), as well as using special technological methods (lowering the temperature of the mold).
Areas of use:
Polymeric materials, including polypropylene, find wide application and ensure the efficiency of economic development and increase of competitiveness of products in consumer industries due to the replacement of expensive materials, reducing the material consumption, the formation of advanced technologies for processing materials, creating new generations of equipment.
The possibility of obtaining a wide range of modified materials based on polypropylene from blended thermoplastic elastomers to high-modulus high-strength plastics, ecological purity of products, technological processing and recycling contribute to the fact that polypropylene has recently replaced polyvinyl chloride, ABS plastic, and high impact polystyrene from the world market of plastics. PP penetrated all the dominant sectors of the economy: electronics, electrical engineering, engineering, automotive, instrument making, transport, construction and many others.
Polypropylene is sometimes called the "king" of plastics. It is known that polypropylene is not the most popular polymer, skipping ahead in the leader list at least polyethylene and polyvinylchloride. However, to date, polypropylene is out of competition in terms of production growth rates. The scope of its application is rapidly expanding. And this despite the fact that all the scientific and technical potential of this polymer has not yet been realized.
|Strength at break, kg/cm2||260-400|
|Relative elongation at break,%||200-700|
|Melting point, ºС||160-170|
|Glass transition temperature, ºС||-10...-20|
|Degree of crystallinity,%||50-75|
|Frost resistance, ºС||-10 и ниже|
|Thermal conductivity, cal/sec × cm × deg||0,00033|
|Specific heat, cal/g × deg||0,40-0,50|
|Coefficient of volumetric expansion at 20 ºС||0,00033|
|Moisture absorption over 30 days at 20 °C, %||0,03|
|The tangent of the dielectric loss angle at 10 ^ 6 Hz||(3-5)10^-4|
|Dielectric permeability at 10 ^ 6 Hz||2,2|
|Specific volumetric electrical resistance, Ohms × cm||10^17|
|Specific surface electrical resistance, Ohm||10^16|
|Electric strength on alternating current on plates 1 mm thick, sq/mm||30-35|
The values given in the table are indicative, they should not be considered as absolutely accurate.
INEX supplies PP on an individual request in accordance with the needs of the customer's production. There are primary and secondary PP granules.